/*!
 * Less - Leaner CSS v2.5.1
 * http://lesscss.org
 *
 * Copyright (c) 2009-2015, Alexis Sellier <self@cloudhead.net>
 * Licensed under the Apache v2 License.
 *
 */

/** * @license Apache v2
 */

(function(f) {
    if (typeof exports === "object" && typeof module !== "undefined") { module.exports = f() } else if (typeof define === "function" && define.amd) { define([], f) } else {
        var g;
        if (typeof window !== "undefined") { g = window } else if (typeof global !== "undefined") { g = global } else if (typeof self !== "undefined") { g = self } else { g = this }
        g.less = f()
    }
})(function() {
    var define, module, exports;
    return (function e(t, n, r) {
        function s(o, u) {
            if (!n[o]) {
                if (!t[o]) { var a = typeof require == "function" && require; if (!u && a) return a(o, !0); if (i) return i(o, !0); var f = new Error("Cannot find module '" + o + "'"); throw f.code = "MODULE_NOT_FOUND", f }
                var l = n[o] = { exports: {} };
                t[o][0].call(l.exports, function(e) { var n = t[o][1][e]; return s(n ? n : e) }, l, l.exports, e, t, n, r)
            }
            return n[o].exports
        }
        var i = typeof require == "function" && require;
        for (var o = 0; o < r.length; o++) s(r[o]);
        return s
    })({
        1: [function(require, module, exports) {
            var addDataAttr = require("./utils").addDataAttr,
                browser = require("./browser");

            module.exports = function(window, options) {

                // use options from the current script tag data attribues
                addDataAttr(options, browser.currentScript(window));

                if (options.isFileProtocol === undefined) {
                    options.isFileProtocol = /^(file|(chrome|safari)(-extension)?|resource|qrc|app):/.test(window.location.protocol);
                }

                // Load styles asynchronously (default: false)
                //
                // This is set to `false` by default, so that the body
                // doesn't start loading before the stylesheets are parsed.
                // Setting this to `true` can result in flickering.
                //
                options.async = options.async || false;
                options.fileAsync = options.fileAsync || false;

                // Interval between watch polls
                options.poll = options.poll || (options.isFileProtocol ? 1000 : 1500);

                options.env = options.env || (window.location.hostname == '127.0.0.1' ||
                    window.location.hostname == '0.0.0.0' ||
                    window.location.hostname == 'localhost' ||
                    (window.location.port &&
                        window.location.port.length > 0) ||
                    options.isFileProtocol ? 'development' :
                    'production');

                var dumpLineNumbers = /!dumpLineNumbers:(comments|mediaquery|all)/.exec(window.location.hash);
                if (dumpLineNumbers) {
                    options.dumpLineNumbers = dumpLineNumbers[1];
                }

                if (options.useFileCache === undefined) {
                    options.useFileCache = true;
                }

                if (options.onReady === undefined) {
                    options.onReady = true;
                }

            };

        }, { "./browser": 3, "./utils": 9 }],
        2: [function(require, module, exports) {
            /**
             * Kicks off less and compiles any stylesheets
             * used in the browser distributed version of less
             * to kick-start less using the browser api
             */
            /*global window */

            // shim Promise if required
            require('promise/polyfill.js');

            var options = window.less || {};
            require("./add-default-options")(window, options);

            var less = module.exports = require("./index")(window, options);

            window.less = less;

            if (options.onReady) {
                if (/!watch/.test(window.location.hash)) {
                    less.watch();
                }

                less.registerStylesheetsImmediately();
                less.pageLoadFinished = less.refresh(less.env === 'development');
            }

        }, { "./add-default-options": 1, "./index": 7, "promise/polyfill.js": 94 }],
        3: [function(require, module, exports) {
            var utils = require("./utils");
            module.exports = {
                createCSS: function(document, styles, sheet) {
                    // Strip the query-string
                    var href = sheet.href || '';

                    // If there is no title set, use the filename, minus the extension
                    var id = 'less:' + (sheet.title || utils.extractId(href));

                    // If this has already been inserted into the DOM, we may need to replace it
                    var oldStyleNode = document.getElementById(id);
                    var keepOldStyleNode = false;

                    // Create a new stylesheet node for insertion or (if necessary) replacement
                    var styleNode = document.createElement('style');
                    styleNode.setAttribute('type', 'text/css');
                    if (sheet.media) {
                        styleNode.setAttribute('media', sheet.media);
                    }
                    styleNode.id = id;

                    if (!styleNode.styleSheet) {
                        styleNode.appendChild(document.createTextNode(styles));

                        // If new contents match contents of oldStyleNode, don't replace oldStyleNode
                        keepOldStyleNode = (oldStyleNode !== null && oldStyleNode.childNodes.length > 0 && styleNode.childNodes.length > 0 &&
                            oldStyleNode.firstChild.nodeValue === styleNode.firstChild.nodeValue);
                    }

                    var head = document.getElementsByTagName('head')[0];

                    // If there is no oldStyleNode, just append; otherwise, only append if we need
                    // to replace oldStyleNode with an updated stylesheet
                    if (oldStyleNode === null || keepOldStyleNode === false) {
                        var nextEl = sheet && sheet.nextSibling || null;
                        if (nextEl) {
                            nextEl.parentNode.insertBefore(styleNode, nextEl);
                        } else {
                            head.appendChild(styleNode);
                        }
                    }
                    if (oldStyleNode && keepOldStyleNode === false) {
                        oldStyleNode.parentNode.removeChild(oldStyleNode);
                    }

                    // For IE.
                    // This needs to happen *after* the style element is added to the DOM, otherwise IE 7 and 8 may crash.
                    // See http://social.msdn.microsoft.com/Forums/en-US/7e081b65-878a-4c22-8e68-c10d39c2ed32/internet-explorer-crashes-appending-style-element-to-head
                    if (styleNode.styleSheet) {
                        try {
                            styleNode.styleSheet.cssText = styles;
                        } catch (e) {
                            throw new Error("Couldn't reassign styleSheet.cssText.");
                        }
                    }
                },
                currentScript: function(window) {
                    var document = window.document;
                    return document.currentScript || (function() {
                        var scripts = document.getElementsByTagName("script");
                        return scripts[scripts.length - 1];
                    })();
                }
            };

        }, { "./utils": 9 }],
        4: [function(require, module, exports) {
            // Cache system is a bit outdated and could do with work

            module.exports = function(window, options, logger) {
                var cache = null;
                if (options.env !== 'development') {
                    try {
                        cache = (typeof window.localStorage === 'undefined') ? null : window.localStorage;
                    } catch (_) {}
                }
                return {
                    setCSS: function(path, lastModified, styles) {
                        if (cache) {
                            logger.info('saving ' + path + ' to cache.');
                            try {
                                cache.setItem(path, styles);
                                cache.setItem(path + ':timestamp', lastModified);
                            } catch (e) {
                                //TODO - could do with adding more robust error handling
                                logger.error('failed to save "' + path + '" to local storage for caching.');
                            }
                        }
                    },
                    getCSS: function(path, webInfo) {
                        var css = cache && cache.getItem(path),
                            timestamp = cache && cache.getItem(path + ':timestamp');

                        if (timestamp && webInfo.lastModified &&
                            (new Date(webInfo.lastModified).valueOf() ===
                                new Date(timestamp).valueOf())) {
                            // Use local copy
                            return css;
                        }
                    }
                };
            };

        }, {}],
        5: [function(require, module, exports) {
            var utils = require("./utils"),
                browser = require("./browser");

            module.exports = function(window, less, options) {

                function errorHTML(e, rootHref) {
                    var id = 'less-error-message:' + utils.extractId(rootHref || "");
                    var template = '<li><label>{line}</label><pre class="{class}">{content}</pre></li>';
                    var elem = window.document.createElement('div'),
                        timer, content, errors = [];
                    var filename = e.filename || rootHref;
                    var filenameNoPath = filename.match(/([^\/]+(\?.*)?)$/)[1];

                    elem.id = id;
                    elem.className = "less-error-message";

                    content = '<h3>' + (e.type || "Syntax") + "Error: " + (e.message || 'There is an error in your .less file') +
                        '</h3>' + '<p>in <a href="' + filename + '">' + filenameNoPath + "</a> ";

                    var errorline = function(e, i, classname) {
                        if (e.extract[i] !== undefined) {
                            errors.push(template.replace(/\{line\}/, (parseInt(e.line, 10) || 0) + (i - 1))
                                .replace(/\{class\}/, classname)
                                .replace(/\{content\}/, e.extract[i]));
                        }
                    };

                    if (e.extract) {
                        errorline(e, 0, '');
                        errorline(e, 1, 'line');
                        errorline(e, 2, '');
                        content += 'on line ' + e.line + ', column ' + (e.column + 1) + ':</p>' +
                            '<ul>' + errors.join('') + '</ul>';
                    }
                    if (e.stack && (e.extract || options.logLevel >= 4)) {
                        content += '<br/>Stack Trace</br />' + e.stack.split('\n').slice(1).join('<br/>');
                    }
                    elem.innerHTML = content;

                    // CSS for error messages
                    browser.createCSS(window.document, [
                        '.less-error-message ul, .less-error-message li {',
                        'list-style-type: none;',
                        'margin-right: 15px;',
                        'padding: 4px 0;',
                        'margin: 0;',
                        '}',
                        '.less-error-message label {',
                        'font-size: 12px;',
                        'margin-right: 15px;',
                        'padding: 4px 0;',
                        'color: #cc7777;',
                        '}',
                        '.less-error-message pre {',
                        'color: #dd6666;',
                        'padding: 4px 0;',
                        'margin: 0;',
                        'display: inline-block;',
                        '}',
                        '.less-error-message pre.line {',
                        'color: #ff0000;',
                        '}',
                        '.less-error-message h3 {',
                        'font-size: 20px;',
                        'font-weight: bold;',
                        'padding: 15px 0 5px 0;',
                        'margin: 0;',
                        '}',
                        '.less-error-message a {',
                        'color: #10a',
                        '}',
                        '.less-error-message .error {',
                        'color: red;',
                        'font-weight: bold;',
                        'padding-bottom: 2px;',
                        'border-bottom: 1px dashed red;',
                        '}'
                    ].join('\n'), { title: 'error-message' });

                    elem.style.cssText = [
                        "font-family: Arial, sans-serif",
                        "border: 1px solid #e00",
                        "background-color: #eee",
                        "border-radius: 5px",
                        "-webkit-border-radius: 5px",
                        "-moz-border-radius: 5px",
                        "color: #e00",
                        "padding: 15px",
                        "margin-bottom: 15px"
                    ].join(';');

                    if (options.env === 'development') {
                        timer = setInterval(function() {
                            var document = window.document,
                                body = document.body;
                            if (body) {
                                if (document.getElementById(id)) {
                                    body.replaceChild(elem, document.getElementById(id));
                                } else {
                                    body.insertBefore(elem, body.firstChild);
                                }
                                clearInterval(timer);
                            }
                        }, 10);
                    }
                }

                function error(e, rootHref) {
                    if (!options.errorReporting || options.errorReporting === "html") {
                        errorHTML(e, rootHref);
                    } else if (options.errorReporting === "console") {
                        errorConsole(e, rootHref);
                    } else if (typeof options.errorReporting === 'function') {
                        options.errorReporting("add", e, rootHref);
                    }
                }

                function removeErrorHTML(path) {
                    var node = window.document.getElementById('less-error-message:' + utils.extractId(path));
                    if (node) {
                        node.parentNode.removeChild(node);
                    }
                }

                function removeErrorConsole(path) {
                    //no action
                }

                function removeError(path) {
                    if (!options.errorReporting || options.errorReporting === "html") {
                        removeErrorHTML(path);
                    } else if (options.errorReporting === "console") {
                        removeErrorConsole(path);
                    } else if (typeof options.errorReporting === 'function') {
                        options.errorReporting("remove", path);
                    }
                }

                function errorConsole(e, rootHref) {
                    var template = '{line} {content}';
                    var filename = e.filename || rootHref;
                    var errors = [];
                    var content = (e.type || "Syntax") + "Error: " + (e.message || 'There is an error in your .less file') +
                        " in " + filename + " ";

                    var errorline = function(e, i, classname) {
                        if (e.extract[i] !== undefined) {
                            errors.push(template.replace(/\{line\}/, (parseInt(e.line, 10) || 0) + (i - 1))
                                .replace(/\{class\}/, classname)
                                .replace(/\{content\}/, e.extract[i]));
                        }
                    };

                    if (e.extract) {
                        errorline(e, 0, '');
                        errorline(e, 1, 'line');
                        errorline(e, 2, '');
                        content += 'on line ' + e.line + ', column ' + (e.column + 1) + ':\n' +
                            errors.join('\n');
                    }
                    if (e.stack && (e.extract || options.logLevel >= 4)) {
                        content += '\nStack Trace\n' + e.stack;
                    }
                    less.logger.error(content);
                }

                return {
                    add: error,
                    remove: removeError
                };
            };

        }, { "./browser": 3, "./utils": 9 }],
        6: [function(require, module, exports) {
            /*global window, XMLHttpRequest */

            module.exports = function(options, logger) {

                var AbstractFileManager = require("../less/environment/abstract-file-manager.js");

                var fileCache = {};

                //TODOS - move log somewhere. pathDiff and doing something similar in node. use pathDiff in the other browser file for the initial load

                function getXMLHttpRequest() {
                    if (window.XMLHttpRequest && (window.location.protocol !== "file:" || !("ActiveXObject" in window))) {
                        return new XMLHttpRequest();
                    } else {
                        try {
                            /*global ActiveXObject */
                            return new ActiveXObject("Microsoft.XMLHTTP");
                        } catch (e) {
                            logger.error("browser doesn't support AJAX.");
                            return null;
                        }
                    }
                }

                var FileManager = function() {};

                FileManager.prototype = new AbstractFileManager();

                FileManager.prototype.alwaysMakePathsAbsolute = function alwaysMakePathsAbsolute() {
                    return true;
                };
                FileManager.prototype.join = function join(basePath, laterPath) {
                    if (!basePath) {
                        return laterPath;
                    }
                    return this.extractUrlParts(laterPath, basePath).path;
                };
                FileManager.prototype.doXHR = function doXHR(url, type, callback, errback) {

                    var xhr = getXMLHttpRequest();
                    var async = options.isFileProtocol ? options.fileAsync : options.async;

                    if (typeof xhr.overrideMimeType === 'function') {
                        xhr.overrideMimeType('text/css');
                    }
                    logger.debug("XHR: Getting '" + url + "'");
                    xhr.open('GET', url, async);
                    xhr.setRequestHeader('Accept', type || 'text/x-less, text/css; q=0.9, */*; q=0.5');
                    xhr.send(null);

                    function handleResponse(xhr, callback, errback) {
                        if (xhr.status >= 200 && xhr.status < 300) {
                            callback(xhr.responseText,
                                xhr.getResponseHeader("Last-Modified"));
                        } else if (typeof errback === 'function') {
                            errback(xhr.status, url);
                        }
                    }

                    if (options.isFileProtocol && !options.fileAsync) {
                        if (xhr.status === 0 || (xhr.status >= 200 && xhr.status < 300)) {
                            callback(xhr.responseText);
                        } else {
                            errback(xhr.status, url);
                        }
                    } else if (async) {
                        xhr.onreadystatechange = function() {
                            if (xhr.readyState == 4) {
                                handleResponse(xhr, callback, errback);
                            }
                        };
                    } else {
                        handleResponse(xhr, callback, errback);
                    }
                };
                FileManager.prototype.supports = function(filename, currentDirectory, options, environment) {
                    return true;
                };

                FileManager.prototype.clearFileCache = function() {
                    fileCache = {};
                };

                FileManager.prototype.loadFile = function loadFile(filename, currentDirectory, options, environment, callback) {
                    if (currentDirectory && !this.isPathAbsolute(filename)) {
                        filename = currentDirectory + filename;
                    }

                    options = options || {};

                    // sheet may be set to the stylesheet for the initial load or a collection of properties including
                    // some context variables for imports
                    var hrefParts = this.extractUrlParts(filename, window.location.href);
                    var href = hrefParts.url;

                    if (options.useFileCache && fileCache[href]) {
                        try {
                            var lessText = fileCache[href];
                            callback(null, { contents: lessText, filename: href, webInfo: { lastModified: new Date() } });
                        } catch (e) {
                            callback({ filename: href, message: "Error loading file " + href + " error was " + e.message });
                        }
                        return;
                    }

                    this.doXHR(href, options.mime, function doXHRCallback(data, lastModified) {
                        // per file cache
                        fileCache[href] = data;

                        // Use remote copy (re-parse)
                        callback(null, { contents: data, filename: href, webInfo: { lastModified: lastModified } });
                    }, function doXHRError(status, url) {
                        callback({ type: 'File', message: "'" + url + "' wasn't found (" + status + ")", href: href });
                    });
                };

                return FileManager;
            };

        }, { "../less/environment/abstract-file-manager.js": 14 }],
        7: [function(require, module, exports) {
            //
            // index.js
            // Should expose the additional browser functions on to the less object
            //
            var addDataAttr = require("./utils").addDataAttr,
                browser = require("./browser");

            module.exports = function(window, options) {
                var document = window.document;
                var less = require('../less')();
                //module.exports = less;
                less.options = options;
                var environment = less.environment,
                    FileManager = require("./file-manager")(options, less.logger),
                    fileManager = new FileManager();
                environment.addFileManager(fileManager);
                less.FileManager = FileManager;

                require("./log-listener")(less, options);
                var errors = require("./error-reporting")(window, less, options);
                var cache = less.cache = options.cache || require("./cache")(window, options, less.logger);

                //Setup user functions
                if (options.functions) {
                    less.functions.functionRegistry.addMultiple(options.functions);
                }

                var typePattern = /^text\/(x-)?less$/;

                function postProcessCSS(styles) { // deprecated, use a plugin for postprocesstasks
                    if (options.postProcessor && typeof options.postProcessor === 'function') {
                        styles = options.postProcessor.call(styles, styles) || styles;
                    }
                    return styles;
                }

                function clone(obj) {
                    var cloned = {};
                    for (var prop in obj) {
                        if (obj.hasOwnProperty(prop)) {
                            cloned[prop] = obj[prop];
                        }
                    }
                    return cloned;
                }

                // only really needed for phantom
                function bind(func, thisArg) {
                    var curryArgs = Array.prototype.slice.call(arguments, 2);
                    return function() {
                        var args = curryArgs.concat(Array.prototype.slice.call(arguments, 0));
                        return func.apply(thisArg, args);
                    };
                }

                function loadStyles(modifyVars) {
                    var styles = document.getElementsByTagName('style'),
                        style;

                    for (var i = 0; i < styles.length; i++) {
                        style = styles[i];
                        if (style.type.match(typePattern)) {
                            var instanceOptions = clone(options);
                            instanceOptions.modifyVars = modifyVars;
                            var lessText = style.innerHTML || '';
                            instanceOptions.filename = document.location.href.replace(/#.*$/, '');

                            /*jshint loopfunc:true */
                            // use closure to store current style
                            less.render(lessText, instanceOptions,
                                bind(function(style, e, result) {
                                    if (e) {
                                        errors.add(e, "inline");
                                    } else {
                                        style.type = 'text/css';
                                        if (style.styleSheet) {
                                            style.styleSheet.cssText = result.css;
                                        } else {
                                            style.innerHTML = result.css;
                                        }
                                    }
                                }, null, style));
                        }
                    }
                }

                function loadStyleSheet(sheet, callback, reload, remaining, modifyVars) {

                    var instanceOptions = clone(options);
                    addDataAttr(instanceOptions, sheet);
                    instanceOptions.mime = sheet.type;

                    if (modifyVars) {
                        instanceOptions.modifyVars = modifyVars;
                    }

                    function loadInitialFileCallback(loadedFile) {

                        var data = loadedFile.contents,
                            path = loadedFile.filename,
                            webInfo = loadedFile.webInfo;

                        var newFileInfo = {
                            currentDirectory: fileManager.getPath(path),
                            filename: path,
                            rootFilename: path,
                            relativeUrls: instanceOptions.relativeUrls
                        };

                        newFileInfo.entryPath = newFileInfo.currentDirectory;
                        newFileInfo.rootpath = instanceOptions.rootpath || newFileInfo.currentDirectory;

                        if (webInfo) {
                            webInfo.remaining = remaining;

                            if (!instanceOptions.modifyVars) {
                                var css = cache.getCSS(path, webInfo);
                                if (!reload && css) {
                                    webInfo.local = true;
                                    callback(null, css, data, sheet, webInfo, path);
                                    return;
                                }
                            }
                        }

                        //TODO add tests around how this behaves when reloading
                        errors.remove(path);

                        instanceOptions.rootFileInfo = newFileInfo;
                        less.render(data, instanceOptions, function(e, result) {
                            if (e) {
                                e.href = path;
                                callback(e);
                            } else {
                                result.css = postProcessCSS(result.css);
                                if (!instanceOptions.modifyVars) {
                                    cache.setCSS(sheet.href, webInfo.lastModified, result.css);
                                }
                                callback(null, result.css, data, sheet, webInfo, path);
                            }
                        });
                    }

                    fileManager.loadFile(sheet.href, null, instanceOptions, environment, function(e, loadedFile) {
                        if (e) {
                            callback(e);
                            return;
                        }
                        loadInitialFileCallback(loadedFile);
                    });
                }

                function loadStyleSheets(callback, reload, modifyVars) {
                    for (var i = 0; i < less.sheets.length; i++) {
                        loadStyleSheet(less.sheets[i], callback, reload, less.sheets.length - (i + 1), modifyVars);
                    }
                }

                function initRunningMode() {
                    if (less.env === 'development') {
                        less.watchTimer = setInterval(function() {
                            if (less.watchMode) {
                                fileManager.clearFileCache();
                                loadStyleSheets(function(e, css, _, sheet, webInfo) {
                                    if (e) {
                                        errors.add(e, e.href || sheet.href);
                                    } else if (css) {
                                        browser.createCSS(window.document, css, sheet);
                                    }
                                });
                            }
                        }, options.poll);
                    }
                }

                //
                // Watch mode
                //
                less.watch = function() {
                    if (!less.watchMode) {
                        less.env = 'development';
                        initRunningMode();
                    }
                    this.watchMode = true;
                    return true;
                };

                less.unwatch = function() {
                    clearInterval(less.watchTimer);
                    this.watchMode = false;
                    return false;
                };

                //
                // Synchronously get all <link> tags with the 'rel' attribute set to
                // "stylesheet/less".
                //
                less.registerStylesheetsImmediately = function() {
                    var links = document.getElementsByTagName('link');
                    less.sheets = [];

                    for (var i = 0; i < links.length; i++) {
                        if (links[i].rel === 'stylesheet/less' || (links[i].rel.match(/stylesheet/) &&
                                (links[i].type.match(typePattern)))) {
                            less.sheets.push(links[i]);
                        }
                    }
                };

                //
                // Asynchronously get all <link> tags with the 'rel' attribute set to
                // "stylesheet/less", returning a Promise.
                //
                less.registerStylesheets = function() {
                    return new Promise(function(resolve, reject) {
                        less.registerStylesheetsImmediately();
                        resolve();
                    });
                };

                //
                // With this function, it's possible to alter variables and re-render
                // CSS without reloading less-files
                //
                less.modifyVars = function(record) {
                    return less.refresh(true, record, false);
                };

                less.refresh = function(reload, modifyVars, clearFileCache) {
                    if ((reload || clearFileCache) && clearFileCache !== false) {
                        fileManager.clearFileCache();
                    }
                    return new Promise(function(resolve, reject) {
                        var startTime, endTime, totalMilliseconds;
                        startTime = endTime = new Date();

                        loadStyleSheets(function(e, css, _, sheet, webInfo) {
                            if (e) {
                                errors.add(e, e.href || sheet.href);
                                reject(e);
                                return;
                            }
                            if (webInfo.local) {
                                less.logger.info("loading " + sheet.href + " from cache.");
                            } else {
                                less.logger.info("rendered " + sheet.href + " successfully.");
                            }
                            browser.createCSS(window.document, css, sheet);
                            less.logger.info("css for " + sheet.href + " generated in " + (new Date() - endTime) + 'ms');
                            if (webInfo.remaining === 0) {
                                totalMilliseconds = new Date() - startTime;
                                less.logger.info("less has finished. css generated in " + totalMilliseconds + 'ms');
                                resolve({
                                    startTime: startTime,
                                    endTime: endTime,
                                    totalMilliseconds: totalMilliseconds,
                                    sheets: less.sheets.length
                                });
                            }
                            endTime = new Date();
                        }, reload, modifyVars);

                        loadStyles(modifyVars);
                    });
                };

                less.refreshStyles = loadStyles;
                return less;
            };

        }, { "../less": 29, "./browser": 3, "./cache": 4, "./error-reporting": 5, "./file-manager": 6, "./log-listener": 8, "./utils": 9 }],
        8: [function(require, module, exports) {
            module.exports = function(less, options) {

                var logLevel_debug = 4,
                    logLevel_info = 3,
                    logLevel_warn = 2,
                    logLevel_error = 1;

                // The amount of logging in the javascript console.
                // 3 - Debug, information and errors
                // 2 - Information and errors
                // 1 - Errors
                // 0 - None
                // Defaults to 2
                options.logLevel = typeof options.logLevel !== 'undefined' ? options.logLevel : (options.env === 'development' ? logLevel_info : logLevel_error);

                if (!options.loggers) {
                    options.loggers = [{
                        debug: function(msg) {
                            if (options.logLevel >= logLevel_debug) {
                                console.log(msg);
                            }
                        },
                        info: function(msg) {
                            if (options.logLevel >= logLevel_info) {
                                console.log(msg);
                            }
                        },
                        warn: function(msg) {
                            if (options.logLevel >= logLevel_warn) {
                                console.warn(msg);
                            }
                        },
                        error: function(msg) {
                            if (options.logLevel >= logLevel_error) {
                                console.error(msg);
                            }
                        }
                    }];
                }
                for (var i = 0; i < options.loggers.length; i++) {
                    less.logger.addListener(options.loggers[i]);
                }
            };

        }, {}],
        9: [function(require, module, exports) {
            module.exports = {
                extractId: function(href) {
                    return href.replace(/^[a-z-]+:\/+?[^\/]+/, '') // Remove protocol & domain
                        .replace(/[\?\&]livereload=\w+/, '') // Remove LiveReload cachebuster
                        .replace(/^\//, '') // Remove root /
                        .replace(/\.[a-zA-Z]+$/, '') // Remove simple extension
                        .replace(/[^\.\w-]+/g, '-') // Replace illegal characters
                        .replace(/\./g, ':'); // Replace dots with colons(for valid id)
                },
                addDataAttr: function(options, tag) {
                    for (var opt in tag.dataset) {
                        if (tag.dataset.hasOwnProperty(opt)) {
                            if (opt === "env" || opt === "dumpLineNumbers" || opt === "rootpath" || opt === "errorReporting") {
                                options[opt] = tag.dataset[opt];
                            } else {
                                try {
                                    options[opt] = JSON.parse(tag.dataset[opt]);
                                } catch (_) {}
                            }
                        }
                    }
                }
            };

        }, {}],
        10: [function(require, module, exports) {
            var contexts = {};
            module.exports = contexts;

            var copyFromOriginal = function copyFromOriginal(original, destination, propertiesToCopy) {
                if (!original) { return; }

                for (var i = 0; i < propertiesToCopy.length; i++) {
                    if (original.hasOwnProperty(propertiesToCopy[i])) {
                        destination[propertiesToCopy[i]] = original[propertiesToCopy[i]];
                    }
                }
            };

            /*
             parse is used whilst parsing
             */
            var parseCopyProperties = [
                // options
                'paths', // option - unmodified - paths to search for imports on
                'relativeUrls', // option - whether to adjust URL's to be relative
                'rootpath', // option - rootpath to append to URL's
                'strictImports', // option -
                'insecure', // option - whether to allow imports from insecure ssl hosts
                'dumpLineNumbers', // option - whether to dump line numbers
                'compress', // option - whether to compress
                'syncImport', // option - whether to import synchronously
                'chunkInput', // option - whether to chunk input. more performant but causes parse issues.
                'mime', // browser only - mime type for sheet import
                'useFileCache', // browser only - whether to use the per file session cache
                // context
                'processImports', // option & context - whether to process imports. if false then imports will not be imported.
                // Used by the import manager to stop multiple import visitors being created.
                'reference', // Used to indicate that the contents are imported by reference
                'pluginManager' // Used as the plugin manager for the session
            ];

            contexts.Parse = function(options) {
                copyFromOriginal(options, this, parseCopyProperties);

                if (typeof this.paths === "string") { this.paths = [this.paths]; }
            };

            var evalCopyProperties = [
                'paths', // additional include paths
                'compress', // whether to compress
                'ieCompat', // whether to enforce IE compatibility (IE8 data-uri)
                'strictMath', // whether math has to be within parenthesis
                'strictUnits', // whether units need to evaluate correctly
                'sourceMap', // whether to output a source map
                'importMultiple', // whether we are currently importing multiple copies
                'urlArgs', // whether to add args into url tokens
                'javascriptEnabled', // option - whether JavaScript is enabled. if undefined, defaults to true
                'pluginManager', // Used as the plugin manager for the session
                'importantScope' // used to bubble up !important statements
            ];

            contexts.Eval = function(options, frames) {
                copyFromOriginal(options, this, evalCopyProperties);

                if (typeof this.paths === "string") { this.paths = [this.paths]; }

                this.frames = frames || [];
                this.importantScope = this.importantScope || [];
            };

            contexts.Eval.prototype.inParenthesis = function() {
                if (!this.parensStack) {
                    this.parensStack = [];
                }
                this.parensStack.push(true);
            };

            contexts.Eval.prototype.outOfParenthesis = function() {
                this.parensStack.pop();
            };

            contexts.Eval.prototype.isMathOn = function() {
                return this.strictMath ? (this.parensStack && this.parensStack.length) : true;
            };

            contexts.Eval.prototype.isPathRelative = function(path) {
                return !/^(?:[a-z-]+:|\/|#)/i.test(path);
            };

            contexts.Eval.prototype.normalizePath = function(path) {
                var
                    segments = path.split("/").reverse(),
                    segment;

                path = [];
                while (segments.length !== 0) {
                    segment = segments.pop();
                    switch (segment) {
                        case ".":
                            break;
                        case "..":
                            if ((path.length === 0) || (path[path.length - 1] === "..")) {
                                path.push(segment);
                            } else {
                                path.pop();
                            }
                            break;
                        default:
                            path.push(segment);
                            break;
                    }
                }

                return path.join("/");
            };

            //todo - do the same for the toCSS ?

        }, {}],
        11: [function(require, module, exports) {
            module.exports = {
                'aliceblue': '#f0f8ff',
                'antiquewhite': '#faebd7',
                'aqua': '#00ffff',
                'aquamarine': '#7fffd4',
                'azure': '#f0ffff',
                'beige': '#f5f5dc',
                'bisque': '#ffe4c4',
                'black': '#000000',
                'blanchedalmond': '#ffebcd',
                'blue': '#0000ff',
                'blueviolet': '#8a2be2',
                'brown': '#a52a2a',
                'burlywood': '#deb887',
                'cadetblue': '#5f9ea0',
                'chartreuse': '#7fff00',
                'chocolate': '#d2691e',
                'coral': '#ff7f50',
                'cornflowerblue': '#6495ed',
                'cornsilk': '#fff8dc',
                'crimson': '#dc143c',
                'cyan': '#00ffff',
                'darkblue': '#00008b',
                'darkcyan': '#008b8b',
                'darkgoldenrod': '#b8860b',
                'darkgray': '#a9a9a9',
                'darkgrey': '#a9a9a9',
                'darkgreen': '#006400',
                'darkkhaki': '#bdb76b',
                'darkmagenta': '#8b008b',
                'darkolivegreen': '#556b2f',
                'darkorange': '#ff8c00',
                'darkorchid': '#9932cc',
                'darkred': '#8b0000',
                'darksalmon': '#e9967a',
                'darkseagreen': '#8fbc8f',
                'darkslateblue': '#483d8b',
                'darkslategray': '#2f4f4f',
                'darkslategrey': '#2f4f4f',
                'darkturquoise': '#00ced1',
                'darkviolet': '#9400d3',
                'deeppink': '#ff1493',
                'deepskyblue': '#00bfff',
                'dimgray': '#696969',
                'dimgrey': '#696969',
                'dodgerblue': '#1e90ff',
                'firebrick': '#b22222',
                'floralwhite': '#fffaf0',
                'forestgreen': '#228b22',
                'fuchsia': '#ff00ff',
                'gainsboro': '#dcdcdc',
                'ghostwhite': '#f8f8ff',
                'gold': '#ffd700',
                'goldenrod': '#daa520',
                'gray': '#808080',
                'grey': '#808080',
                'green': '#008000',
                'greenyellow': '#adff2f',
                'honeydew': '#f0fff0',
                'hotpink': '#ff69b4',
                'indianred': '#cd5c5c',
                'indigo': '#4b0082',
                'ivory': '#fffff0',
                'khaki': '#f0e68c',
                'lavender': '#e6e6fa',
                'lavenderblush': '#fff0f5',
                'lawngreen': '#7cfc00',
                'lemonchiffon': '#fffacd',
                'lightblue': '#add8e6',
                'lightcoral': '#f08080',
                'lightcyan': '#e0ffff',
                'lightgoldenrodyellow': '#fafad2',
                'lightgray': '#d3d3d3',
                'lightgrey': '#d3d3d3',
                'lightgreen': '#90ee90',
                'lightpink': '#ffb6c1',
                'lightsalmon': '#ffa07a',
                'lightseagreen': '#20b2aa',
                'lightskyblue': '#87cefa',
                'lightslategray': '#778899',
                'lightslategrey': '#778899',
                'lightsteelblue': '#b0c4de',
                'lightyellow': '#ffffe0',
                'lime': '#00ff00',
                'limegreen': '#32cd32',
                'linen': '#faf0e6',
                'magenta': '#ff00ff',
                'maroon': '#800000',
                'mediumaquamarine': '#66cdaa',
                'mediumblue': '#0000cd',
                'mediumorchid': '#ba55d3',
                'mediumpurple': '#9370d8',
                'mediumseagreen': '#3cb371',
                'mediumslateblue': '#7b68ee',
                'mediumspringgreen': '#00fa9a',
                'mediumturquoise': '#48d1cc',
                'mediumvioletred': '#c71585',
                'midnightblue': '#191970',
                'mintcream': '#f5fffa',
                'mistyrose': '#ffe4e1',
                'moccasin': '#ffe4b5',
                'navajowhite': '#ffdead',
                'navy': '#000080',
                'oldlace': '#fdf5e6',
                'olive': '#808000',
                'olivedrab': '#6b8e23',
                'orange': '#ffa500',
                'orangered': '#ff4500',
                'orchid': '#da70d6',
                'palegoldenrod': '#eee8aa',
                'palegreen': '#98fb98',
                'paleturquoise': '#afeeee',
                'palevioletred': '#d87093',
                'papayawhip': '#ffefd5',
                'peachpuff': '#ffdab9',
                'peru': '#cd853f',
                'pink': '#ffc0cb',
                'plum': '#dda0dd',
                'powderblue': '#b0e0e6',
                'purple': '#800080',
                'rebeccapurple': '#663399',
                'red': '#ff0000',
                'rosybrown': '#bc8f8f',
                'royalblue': '#4169e1',
                'saddlebrown': '#8b4513',
                'salmon': '#fa8072',
                'sandybrown': '#f4a460',
                'seagreen': '#2e8b57',
                'seashell': '#fff5ee',
                'sienna': '#a0522d',
                'silver': '#c0c0c0',
                'skyblue': '#87ceeb',
                'slateblue': '#6a5acd',
                'slategray': '#708090',
                'slategrey': '#708090',
                'snow': '#fffafa',
                'springgreen': '#00ff7f',
                'steelblue': '#4682b4',
                'tan': '#d2b48c',
                'teal': '#008080',
                'thistle': '#d8bfd8',
                'tomato': '#ff6347',
                'turquoise': '#40e0d0',
                'violet': '#ee82ee',
                'wheat': '#f5deb3',
                'white': '#ffffff',
                'whitesmoke': '#f5f5f5',
                'yellow': '#ffff00',
                'yellowgreen': '#9acd32'
            };
        }, {}],
        12: [function(require, module, exports) {
            module.exports = {
                colors: require("./colors"),
                unitConversions: require("./unit-conversions")
            };

        }, { "./colors": 11, "./unit-conversions": 13 }],
        13: [function(require, module, exports) {
            module.exports = {
                length: {
                    'm': 1,
                    'cm': 0.01,
                    'mm': 0.001,
                    'in': 0.0254,
                    'px': 0.0254 / 96,
                    'pt': 0.0254 / 72,
                    'pc': 0.0254 / 72 * 12
                },
                duration: {
                    's': 1,
                    'ms': 0.001
                },
                angle: {
                    'rad': 1 / (2 * Math.PI),
                    'deg': 1 / 360,
                    'grad': 1 / 400,
                    'turn': 1
                }
            };
        }, {}],
        14: [function(require, module, exports) {
            var abstractFileManager = function() {};

            abstractFileManager.prototype.getPath = function(filename) {
                var j = filename.lastIndexOf('?');
                if (j > 0) {
                    filename = filename.slice(0, j);
                }
                j = filename.lastIndexOf('/');
                if (j < 0) {
                    j = filename.lastIndexOf('\\');
                }
                if (j < 0) {
                    return "";
                }
                return filename.slice(0, j + 1);
            };

            abstractFileManager.prototype.tryAppendExtension = function(path, ext) {
                return /(\.[a-z]*$)|([\?;].*)$/.test(path) ? path : path + ext;
            };

            abstractFileManager.prototype.tryAppendLessExtension = function(path) {
                return this.tryAppendExtension(path, '.less');
            };

            abstractFileManager.prototype.supportsSync = function() {
                return false;
            };

            abstractFileManager.prototype.alwaysMakePathsAbsolute = function() {
                return false;
            };

            abstractFileManager.prototype.isPathAbsolute = function(filename) {
                return (/^(?:[a-z-]+:|\/|\\|#)/i).test(filename);
            };

            abstractFileManager.prototype.join = function(basePath, laterPath) {
                if (!basePath) {
                    return laterPath;
                }
                return basePath + laterPath;
            };
            abstractFileManager.prototype.pathDiff = function pathDiff(url, baseUrl) {
                // diff between two paths to create a relative path

                var urlParts = this.extractUrlParts(url),
                    baseUrlParts = this.extractUrlParts(baseUrl),
                    i, max, urlDirectories, baseUrlDirectories, diff = "";
                if (urlParts.hostPart !== baseUrlParts.hostPart) {
                    return "";
                }
                max = Math.max(baseUrlParts.directories.length, urlParts.directories.length);
                for (i = 0; i < max; i++) {
                    if (baseUrlParts.directories[i] !== urlParts.directories[i]) { break; }
                }
                baseUrlDirectories = baseUrlParts.directories.slice(i);
                urlDirectories = urlParts.directories.slice(i);
                for (i = 0; i < baseUrlDirectories.length - 1; i++) {
                    diff += "../";
                }
                for (i = 0; i < urlDirectories.length - 1; i++) {
                    diff += urlDirectories[i] + "/";
                }
                return diff;
            };
            // helper function, not part of API
            abstractFileManager.prototype.extractUrlParts = function extractUrlParts(url, baseUrl) {
                // urlParts[1] = protocol&hostname || /
                // urlParts[2] = / if path relative to host base
                // urlParts[3] = directories
                // urlParts[4] = filename
                // urlParts[5] = parameters

                var urlPartsRegex = /^((?:[a-z-]+:)?\/+?(?:[^\/\?#]*\/)|([\/\\]))?((?:[^\/\\\?#]*[\/\\])*)([^\/\\\?#]*)([#\?].*)?$/i,
                    urlParts = url.match(urlPartsRegex),
                    returner = {},
                    directories = [],
                    i, baseUrlParts;

                if (!urlParts) {
                    throw new Error("Could not parse sheet href - '" + url + "'");
                }

                // Stylesheets in IE don't always return the full path
                if (baseUrl && (!urlParts[1] || urlParts[2])) {
                    baseUrlParts = baseUrl.match(urlPartsRegex);
                    if (!baseUrlParts) {
                        throw new Error("Could not parse page url - '" + baseUrl + "'");
                    }
                    urlParts[1] = urlParts[1] || baseUrlParts[1] || "";
                    if (!urlParts[2]) {
                        urlParts[3] = baseUrlParts[3] + urlParts[3];
                    }
                }

                if (urlParts[3]) {
                    directories = urlParts[3].replace(/\\/g, "/").split("/");

                    // extract out . before .. so .. doesn't absorb a non-directory
                    for (i = 0; i < directories.length; i++) {
                        if (directories[i] === ".") {
                            directories.splice(i, 1);
                            i -= 1;
                        }
                    }

                    for (i = 0; i < directories.length; i++) {
                        if (directories[i] === ".." && i > 0) {
                            directories.splice(i - 1, 2);
                            i -= 2;
                        }
                    }
                }

                returner.hostPart = urlParts[1];
                returner.directories = directories;
                returner.path = (urlParts[1] || "") + directories.join("/");
                returner.fileUrl = returner.path + (urlParts[4] || "");
                returner.url = returner.fileUrl + (urlParts[5] || "");
                return returner;
            };

            module.exports = abstractFileManager;

        }, {}],
        15: [function(require, module, exports) {
            var logger = require("../logger");
            var environment = function(externalEnvironment, fileManagers) {
                this.fileManagers = fileManagers || [];
                externalEnvironment = externalEnvironment || {};

                var optionalFunctions = ["encodeBase64", "mimeLookup", "charsetLookup", "getSourceMapGenerator"],
                    requiredFunctions = [],
                    functions = requiredFunctions.concat(optionalFunctions);

                for (var i = 0; i < functions.length; i++) {
                    var propName = functions[i],
                        environmentFunc = externalEnvironment[propName];
                    if (environmentFunc) {
                        this[propName] = environmentFunc.bind(externalEnvironment);
                    } else if (i < requiredFunctions.length) {
                        this.warn("missing required function in environment - " + propName);
                    }
                }
            };

            environment.prototype.getFileManager = function(filename, currentDirectory, options, environment, isSync) {

                if (!filename) {
                    logger.warn("getFileManager called with no filename.. Please report this issue. continuing.");
                }
                if (currentDirectory == null) {
                    logger.warn("getFileManager called with null directory.. Please report this issue. continuing.");
                }

                var fileManagers = this.fileManagers;
                if (options.pluginManager) {
                    fileManagers = [].concat(fileManagers).concat(options.pluginManager.getFileManagers());
                }
                for (var i = fileManagers.length - 1; i >= 0; i--) {
                    var fileManager = fileManagers[i];
                    if (fileManager[isSync ? "supportsSync" : "supports"](filename, currentDirectory, options, environment)) {
                        return fileManager;
                    }
                }
                return null;
            };

            environment.prototype.addFileManager = function(fileManager) {
                this.fileManagers.push(fileManager);
            };

            environment.prototype.clearFileManagers = function() {
                this.fileManagers = [];
            };

            module.exports = environment;

        }, { "../logger": 31 }],
        16: [function(require, module, exports) {
            var Color = require("../tree/color"),
                functionRegistry = require("./function-registry");

            // Color Blending
            // ref: http://www.w3.org/TR/compositing-1

            function colorBlend(mode, color1, color2) {
                var ab = color1.alpha,
                    cb, // backdrop
                    as = color2.alpha,
                    cs, // source
                    ar, cr, r = []; // result

                ar = as + ab * (1 - as);
                for (var i = 0; i < 3; i++) {
                    cb = color1.rgb[i] / 255;
                    cs = color2.rgb[i] / 255;
                    cr = mode(cb, cs);
                    if (ar) {
                        cr = (as * cs + ab * (cb -
                            as * (cb + cs - cr))) / ar;
                    }
                    r[i] = cr * 255;
                }

                return new Color(r, ar);
            }

            var colorBlendModeFunctions = {
                multiply: function(cb, cs) {
                    return cb * cs;
                },
                screen: function(cb, cs) {
                    return cb + cs - cb * cs;
                },
                overlay: function(cb, cs) {
                    cb *= 2;
                    return (cb <= 1) ?
                        colorBlendModeFunctions.multiply(cb, cs) :
                        colorBlendModeFunctions.screen(cb - 1, cs);
                },
                softlight: function(cb, cs) {
                    var d = 1,
                        e = cb;
                    if (cs > 0.5) {
                        e = 1;
                        d = (cb > 0.25) ? Math.sqrt(cb) :
                            ((16 * cb - 12) * cb + 4) * cb;
                    }
                    return cb - (1 - 2 * cs) * e * (d - cb);
                },
                hardlight: function(cb, cs) {
                    return colorBlendModeFunctions.overlay(cs, cb);
                },
                difference: function(cb, cs) {
                    return Math.abs(cb - cs);
                },
                exclusion: function(cb, cs) {
                    return cb + cs - 2 * cb * cs;
                },

                // non-w3c functions:
                average: function(cb, cs) {
                    return (cb + cs) / 2;
                },
                negation: function(cb, cs) {
                    return 1 - Math.abs(cb + cs - 1);
                }
            };

            for (var f in colorBlendModeFunctions) {
                if (colorBlendModeFunctions.hasOwnProperty(f)) {
                    colorBlend[f] = colorBlend.bind(null, colorBlendModeFunctions[f]);
                }
            }

            functionRegistry.addMultiple(colorBlend);

        }, { "../tree/color": 48, "./function-registry": 21 }],
        17: [function(require, module, exports) {
            var Dimension = require("../tree/dimension"),
                Color = require("../tree/color"),
                Quoted = require("../tree/quoted"),
                Anonymous = require("../tree/anonymous"),
                functionRegistry = require("./function-registry"),
                colorFunctions;

            function clamp(val) {
                return Math.min(1, Math.max(0, val));
            }

            function hsla(color) {
                return colorFunctions.hsla(color.h, color.s, color.l, color.a);
            }

            function number(n) {
                if (n instanceof Dimension) {
                    return parseFloat(n.unit.is('%') ? n.value / 100 : n.value);
                } else if (typeof n === 'number') {
                    return n;
                } else {
                    throw {
                        type: "Argument",
                        message: "color functions take numbers as parameters"
                    };
                }
            }

            function scaled(n, size) {
                if (n instanceof Dimension && n.unit.is('%')) {
                    return parseFloat(n.value * size / 100);
                } else {
                    return number(n);
                }
            }
            colorFunctions = {
                rgb: function(r, g, b) {
                    return colorFunctions.rgba(r, g, b, 1.0);
                },
                rgba: function(r, g, b, a) {
                    var rgb = [r, g, b].map(function(c) { return scaled(c, 255); });
                    a = number(a);
                    return new Color(rgb, a);
                },
                hsl: function(h, s, l) {
                    return colorFunctions.hsla(h, s, l, 1.0);
                },
                hsla: function(h, s, l, a) {
                    function hue(h) {
                        h = h < 0 ? h + 1 : (h > 1 ? h - 1 : h);
                        if (h * 6 < 1) {
                            return m1 + (m2 - m1) * h * 6;
                        } else if (h * 2 < 1) {
                            return m2;
                        } else if (h * 3 < 2) {
                            return m1 + (m2 - m1) * (2 / 3 - h) * 6;
                        } else {
                            return m1;
                        }
                    }

                    h = (number(h) % 360) / 360;
                    s = clamp(number(s));
                    l = clamp(number(l));
                    a = clamp(number(a));

                    var m2 = l <= 0.5 ? l * (s + 1) : l + s - l * s;
                    var m1 = l * 2 - m2;

                    return colorFunctions.rgba(hue(h + 1 / 3) * 255,
                        hue(h) * 255,
                        hue(h - 1 / 3) * 255,
                        a);
                },

                hsv: function(h, s, v) {
                    return colorFunctions.hsva(h, s, v, 1.0);
                },

                hsva: function(h, s, v, a) {
                    h = ((number(h) % 360) / 360) * 360;
                    s = number(s);
                    v = number(v);
                    a = number(a);

                    var i, f;
                    i = Math.floor((h / 60) % 6);
                    f = (h / 60) - i;

                    var vs = [v,
                        v * (1 - s),
                        v * (1 - f * s),
                        v * (1 - (1 - f) * s)
                    ];
                    var perm = [
                        [0, 3, 1],
                        [2, 0, 1],
                        [1, 0, 3],
                        [1, 2, 0],
                        [3, 1, 0],
                        [0, 1, 2]
                    ];

                    return colorFunctions.rgba(vs[perm[i][0]] * 255,
                        vs[perm[i][1]] * 255,
                        vs[perm[i][2]] * 255,
                        a);
                },

                hue: function(color) {
                    return new Dimension(color.toHSL().h);
                },
                saturation: function(color) {
                    return new Dimension(color.toHSL().s * 100, '%');
                },
                lightness: function(color) {
                    return new Dimension(color.toHSL().l * 100, '%');
                },
                hsvhue: function(color) {
                    return new Dimension(color.toHSV().h);
                },
                hsvsaturation: function(color) {
                    return new Dimension(color.toHSV().s * 100, '%');
                },
                hsvvalue: function(color) {
                    return new Dimension(color.toHSV().v * 100, '%');
                },
                red: function(color) {
                    return new Dimension(color.rgb[0]);
                },
                green: function(color) {
                    return new Dimension(color.rgb[1]);
                },
                blue: function(color) {
                    return new Dimension(color.rgb[2]);
                },
                alpha: function(color) {
                    return new Dimension(color.toHSL().a);
                },
                luma: function(color) {
                    return new Dimension(color.luma() * color.alpha * 100, '%');
                },
                luminance: function(color) {
                    var luminance =
                        (0.2126 * color.rgb[0] / 255) +
                        (0.7152 * color.rgb[1] / 255) +
                        (0.0722 * color.rgb[2] / 255);

                    return new Dimension(luminance * color.alpha * 100, '%');
                },
                saturate: function(color, amount, method) {
                    // filter: saturate(3.2);
                    // should be kept as is, so check for color
                    if (!color.rgb) {
                        return null;
                    }
                    var hsl = color.toHSL();

                    if (typeof method !== "undefined" && method.value === "relative") {
                        hsl.s += hsl.s * amount.value / 100;
                    } else {
                        hsl.s += amount.value / 100;
                    }
                    hsl.s = clamp(hsl.s);
                    return hsla(hsl);
                },
                desaturate: function(color, amount, method) {
                    var hsl = color.toHSL();

                    if (typeof method !== "undefined" && method.value === "relative") {
                        hsl.s -= hsl.s * amount.value / 100;
                    } else {
                        hsl.s -= amount.value / 100;
                    }
                    hsl.s = clamp(hsl.s);
                    return hsla(hsl);
                },
                lighten: function(color, amount, method) {
                    var hsl = color.toHSL();

                    if (typeof method !== "undefined" && method.value === "relative") {
                        hsl.l += hsl.l * amount.value / 100;
                    } else {
                        hsl.l += amount.value / 100;
                    }
                    hsl.l = clamp(hsl.l);
                    return hsla(hsl);
                },
                darken: function(color, amount, method) {
                    var hsl = color.toHSL();

                    if (typeof method !== "undefined" && method.value === "relative") {
                        hsl.l -= hsl.l * amount.value / 100;
                    } else {
                        hsl.l -= amount.value / 100;
                    }
                    hsl.l = clamp(hsl.l);
                    return hsla(hsl);
                },
                fadein: function(color, amount, method) {
                    var hsl = color.toHSL();

                    if (typeof method !== "undefined" && method.value === "relative") {
                        hsl.a += hsl.a * amount.value / 100;
                    } else {
                        hsl.a += amount.value / 100;
                    }
                    hsl.a = clamp(hsl.a);
                    return hsla(hsl);
                },
                fadeout: function(color, amount, method) {
                    var hsl = color.toHSL();

                    if (typeof method !== "undefined" && method.value === "relative") {
                        hsl.a -= hsl.a * amount.value / 100;
                    } else {
                        hsl.a -= amount.value / 100;
                    }
                    hsl.a = clamp(hsl.a);
                    return hsla(hsl);
                },
                fade: function(color, amount) {
                    var hsl = color.toHSL();

                    hsl.a = amount.value / 100;
                    hsl.a = clamp(hsl.a);
                    return hsla(hsl);
                },
                spin: function(color, amount) {
                    var hsl = color.toHSL();
                    var hue = (hsl.h + amount.value) % 360;

                    hsl.h = hue < 0 ? 360 + hue : hue;

                    return hsla(hsl);
                },
                //
                // Copyright (c) 2006-2009 Hampton Catlin, Nathan Weizenbaum, and Chris Eppstein
                // http://sass-lang.com
                //
                mix: function(color1, color2, weight) {
                    if (!color1.toHSL || !color2.toHSL) {
                        console.log(color2.type);
                        console.dir(color2);
                    }
                    if (!weight) {
                        weight = new Dimension(50);
                    }
                    var p = weight.value / 100.0;
                    var w = p * 2 - 1;
                    var a = color1.toHSL().a - color2.toHSL().a;

                    var w1 = (((w * a == -1) ? w : (w + a) / (1 + w * a)) + 1) / 2.0;
                    var w2 = 1 - w1;

                    var rgb = [color1.rgb[0] * w1 + color2.rgb[0] * w2,
                        color1.rgb[1] * w1 + color2.rgb[1] * w2,
                        color1.rgb[2] * w1 + color2.rgb[2] * w2
                    ];

                    var alpha = color1.alpha * p + color2.alpha * (1 - p);

                    return new Color(rgb, alpha);
                },
                greyscale: function(color) {
                    return colorFunctions.desaturate(color, new Dimension(100));
                },
                contrast: function(color, dark, light, threshold) {
                    // filter: contrast(3.2);
                    // should be kept as is, so check for color
                    if (!color.rgb) {
                        return null;
                    }
                    if (typeof light === 'undefined') {
                        light = colorFunctions.rgba(255, 255, 255, 1.0);
                    }
                    if (typeof dark === 'undefined') {
                        dark = colorFunctions.rgba(0, 0, 0, 1.0);
                    }
                    //Figure out which is actually light and dark!
                    if (dark.luma() > light.luma()) {
                        var t = light;
                        light = dark;
                        dark = t;
                    }
                    if (typeof threshold === 'undefined') {
                        threshold = 0.43;
                    } else {
                        threshold = number(threshold);
                    }
                    if (color.luma() < threshold) {
                        return light;
                    } else {
                        return dark;
                    }
                },
                argb: function(color) {
                    return new Anonymous(color.toARGB());
                },
                color: function(c) {
                    if ((c instanceof Quoted) &&
                        (/^#([a-f0-9]{6}|[a-f0-9]{3})$/i.test(c.value))) {
                        return new Color(c.value.slice(1));
                    }
                    if ((c instanceof Color) || (c = Color.fromKeyword(c.value))) {
                        c.value = undefined;
                        return c;
                    }
                    throw {
                        type: "Argument",
                        message: "argument must be a color keyword or 3/6 digit hex e.g. #FFF"
                    };
                },
                tint: function(color, amount) {
                    return colorFunctions.mix(colorFunctions.rgb(255, 255, 255), color, amount);
                },
                shade: function(color, amount) {
                    return colorFunctions.mix(colorFunctions.rgb(0, 0, 0), color, amount);
                }
            };
            functionRegistry.addMultiple(colorFunctions);

        }, { "../tree/anonymous": 44, "../tree/color": 48, "../tree/dimension": 54, "../tree/quoted": 71, "./function-registry": 21 }],
        18: [function(require, module, exports) {
            module.exports = function(environment) {
                var Quoted = require("../tree/quoted"),
                    URL = require("../tree/url"),
                    functionRegistry = require("./function-registry"),
                    fallback = function(functionThis, node) {
                        return new URL(node, functionThis.index, functionThis.currentFileInfo).eval(functionThis.context);
                    },
                    logger = require('../logger');

                functionRegistry.add("data-uri", function(mimetypeNode, filePathNode) {

                    if (!filePathNode) {
                        filePathNode = mimetypeNode;
                        mimetypeNode = null;
                    }

                    var mimetype = mimetypeNode && mimetypeNode.value;
                    var filePath = filePathNode.value;
                    var currentFileInfo = this.currentFileInfo;
                    var currentDirectory = currentFileInfo.relativeUrls ?
                        currentFileInfo.currentDirectory : currentFileInfo.entryPath;

                    var fragmentStart = filePath.indexOf('#');
                    var fragment = '';
                    if (fragmentStart !== -1) {
                        fragment = filePath.slice(fragmentStart);
                        filePath = filePath.slice(0, fragmentStart);
                    }

                    var fileManager = environment.getFileManager(filePath, currentDirectory, this.context, environment, true);

                    if (!fileManager) {
                        return fallback(this, filePathNode);
                    }

                    var useBase64 = false;

                    // detect the mimetype if not given
                    if (!mimetypeNode) {

                        mimetype = environment.mimeLookup(filePath);

                        if (mimetype === "image/svg+xml") {
                            useBase64 = false;
                        } else {
                            // use base 64 unless it's an ASCII or UTF-8 format
                            var charset = environment.charsetLookup(mimetype);
                            useBase64 = ['US-ASCII', 'UTF-8'].indexOf(charset) < 0;
                        }
                        if (useBase64) { mimetype += ';base64'; }
                    } else {
                        useBase64 = /;base64$/.test(mimetype);
                    }

                    var fileSync = fileManager.loadFileSync(filePath, currentDirectory, this.context, environment);
                    if (!fileSync.contents) {
                        logger.warn("Skipped data-uri embedding of " + filePath + " because file not found");
                        return fallback(this, filePathNode || mimetypeNode);
                    }
                    var buf = fileSync.contents;
                    if (useBase64 && !environment.encodeBase64) {
                        return fallback(this, filePathNode);
                    }

                    buf = useBase64 ? environment.encodeBase64(buf) : encodeURIComponent(buf);

                    var uri = "data:" + mimetype + ',' + buf + fragment;

                    // IE8 cannot handle a data-uri larger than 32,768 characters. If this is exceeded
                    // and the --ieCompat flag is enabled, return a normal url() instead.
                    var DATA_URI_MAX = 32768;
                    if (uri.length >= DATA_URI_MAX) {

                        if (this.context.ieCompat !== false) {
                            logger.warn("Skipped data-uri embedding of " + filePath + " because its size (" + uri.length +
                                " characters) exceeds IE8-safe " + DATA_URI_MAX + " characters!");

                            return fallback(this, filePathNode || mimetypeNode);
                        }
                    }

                    return new URL(new Quoted('"' + uri + '"', uri, false, this.index, this.currentFileInfo), this.index, this.currentFileInfo);
                });
            };

        }, { "../logger": 31, "../tree/quoted": 71, "../tree/url": 78, "./function-registry": 21 }],
        19: [function(require, module, exports) {
            var Keyword = require("../tree/keyword"),
                functionRegistry = require("./function-registry");

            var defaultFunc = {
                eval: function() {
                    var v = this.value_,
                        e = this.error_;
                    if (e) {
                        throw e;
                    }
                    if (v != null) {
                        return v ? Keyword.True : Keyword.False;
                    }
                },
                value: function(v) {
                    this.value_ = v;
                },
                error: function(e) {
                    this.error_ = e;
                },
                reset: function() {
                    this.value_ = this.error_ = null;
                }
            };

            functionRegistry.add("default", defaultFunc.eval.bind(defaultFunc));

            module.exports = defaultFunc;

        }, { "../tree/keyword": 63, "./function-registry": 21 }],
        20: [function(require, module, exports) {
            var Expression = require("../tree/expression");

            var functionCaller = function(name, context, index, currentFileInfo) {
                this.name = name.toLowerCase();
                this.index = index;
                this.context = context;
                this.currentFileInfo = currentFileInfo;

                this.func = context.frames[0].functionRegistry.get(this.name);
            };
            functionCaller.prototype.isValid = function() {
                return Boolean(this.func);
            };
            functionCaller.prototype.call = function(args) {

                // This code is terrible and should be replaced as per this issue...
                // https://github.com/less/less.js/issues/2477
                if (Array.isArray(args)) {
                    args = args.filter(function(item) {
                            if (item.type === "Comment") {
                                return false;
                            }
                            return true;
                        })
                        .map(function(item) {
                            if (item.type === "Expression") {
                                var subNodes = item.value.filter(function(item) {
                                    if (item.type === "Comment") {
                                        return false;
                                    }
                                    return true;
                                });
                                if (subNodes.length === 1) {
                                    return subNodes[0];
                                } else {
                                    return new Expression(subNodes);
                                }
                            }
                            return item;
                        });
                }

                return this.func.apply(this, args);
            };

            module.exports = functionCaller;

        }, { "../tree/expression": 57 }],
        21: [function(require, module, exports) {
            function makeRegistry(base) {
                return {
                    _data: {},
                    add: function(name, func) {
                        // precautionary case conversion, as later querying of
                        // the registry by function-caller uses lower case as well.
                        name = name.toLowerCase();

                        if (this._data.hasOwnProperty(name)) {
                            //TODO warn
                        }
                        this._data[name] = func;
                    },
                    addMultiple: function(functions) {
                        Object.keys(functions).forEach(
                            function(name) {
                                this.add(name, functions[name]);
                            }.bind(this));
                    },
                    get: function(name) {
                        return this._data[name] || (base && base.get(name));
                    },
                    inherit: function() {
                        return makeRegistry(this);
                    }
                };
            }

            module.exports = makeRegistry(null);
        }, {}],
        22: [function(require, module, exports) {
            module.exports = function(environment) {
                var functions = {
                    functionRegistry: require("./function-registry"),
                    functionCaller: require("./function-caller")
                };

                //register functions
                require("./default");
                require("./color");
                require("./color-blending");
                require("./data-uri")(environment);
                require("./math");
                require("./number");
                require("./string");
                require("./svg")(environment);
                require("./types");

                return functions;
            };

        }, { "./color": 17, "./color-blending": 16, "./data-uri": 18, "./default": 19, "./function-caller": 20, "./function-registry": 21, "./math": 23, "./number": 24, "./string": 25, "./svg": 26, "./types": 27 }],
        23: [function(require, module, exports) {
            var Dimension = require("../tree/dimension"),
                functionRegistry = require("./function-registry");

            var mathFunctions = {
                // name,  unit
                ceil: null,
                floor: null,
                sqrt: null,
                abs: null,
                tan: "",
                sin: "",
                cos: "",
                atan: "rad",
                asin: "rad",
                acos: "rad"
            };

            function _math(fn, unit, n) {
                if (!(n instanceof Dimension)) {
                    throw { type: "Argument", message: "argument must be a number" };
                }
                if (unit == null) {
                    unit = n.unit;
                } else {
                    n = n.unify();
                }
                return new Dimension(fn(parseFloat(n.value)), unit);
            }

            for (var f in mathFunctions) {
                if (mathFunctions.hasOwnProperty(f)) {
                    mathFunctions[f] = _math.bind(null, Math[f], mathFunctions[f]);
                }
            }

            mathFunctions.round = function(n, f) {
                var fraction = typeof f === "undefined" ? 0 : f.value;
                return _math(function(num) { return num.toFixed(fraction); }, null, n);
            };

            functionRegistry.addMultiple(mathFunctions);

        }, { "../tree/dimension": 54, "./function-registry": 21 }],
        24: [function(require, module, exports) {
            var Dimension = require("../tree/dimension"),
                Anonymous = require("../tree/anonymous"),
                functionRegistry = require("./function-registry");

            var minMax = function(isMin, args) {
                args = Array.prototype.slice.call(args);
                switch (args.length) {
                    case 0:
                        throw { type: "Argument", message: "one or more arguments required" };
                }
                var i, j, current, currentUnified, referenceUnified, unit, unitStatic, unitClone,
                    order = [], // elems only contains original argument values.
                    values = {}; // key is the unit.toString() for unified Dimension values,
                // value is the index into the order array.
                for (i = 0; i < args.length; i++) {
                    current = args[i];
                    if (!(current instanceof Dimension)) {
                        if (Array.isArray(args[i].value)) {
                            Array.prototype.push.apply(args, Array.prototype.slice.call(args[i].value));
                        }
                        continue;
                    }
                    currentUnified = current.unit.toString() === "" && unitClone !== undefined ? new Dimension(current.value, unitClone).unify() : current.unify();
                    unit = currentUnified.unit.toString() === "" && unitStatic !== undefined ? unitStatic : currentUnified.unit.toString();
                    unitStatic = unit !== "" && unitStatic === undefined || unit !== "" && order[0].unify().unit.toString() === "" ? unit : unitStatic;
                    unitClone = unit !== "" && unitClone === undefined ? current.unit.toString() : unitClone;
                    j = values[""] !== undefined && unit !== "" && unit === unitStatic ? values[""] : values[unit];
                    if (j === undefined) {
                        if (unitStatic !== undefined && unit !== unitStatic) {
                            throw { type: "Argument", message: "incompatible types" };
                        }
                        values[unit] = order.length;
                        order.push(current);
                        continue;
                    }
                    referenceUnified = order[j].unit.toString() === "" && unitClone !== undefined ? new Dimension(order[j].value, unitClone).unify() : order[j].unify();
                    if (isMin && currentUnified.value < referenceUnified.value ||
                        !isMin && currentUnified.value > referenceUnified.value) {
                        order[j] = current;
                    }
                }
                if (order.length == 1) {
                    return order[0];
                }
                args = order.map(function(a) { return a.toCSS(this.context); }).join(this.context.compress ? "," : ", ");
                return new Anonymous((isMin ? "min" : "max") + "(" + args + ")");
            };
            functionRegistry.addMultiple({
                min: function() {
                    return minMax(true, arguments);
                },
                max: function() {
                    return minMax(false, arguments);
                },
                convert: function(val, unit) {
                    return val.convertTo(unit.value);
                },
                pi: function() {
                    return new Dimension(Math.PI);
                },
                mod: function(a, b) {
                    return new Dimension(a.value % b.value, a.unit);
                },
                pow: function(x, y) {
                    if (typeof x === "number" && typeof y === "number") {
                        x = new Dimension(x);
                        y = new Dimension(y);
                    } else if (!(x instanceof Dimension) || !(y instanceof Dimension)) {
                        throw { type: "Argument", message: "arguments must be numbers" };
                    }

                    return new Dimension(Math.pow(x.value, y.value), x.unit);
                },
                percentage: function(n) {
                    return new Dimension(n.value * 100, '%');
                }
            });

        }, { "../tree/anonymous": 44, "../tree/dimension": 54, "./function-registry": 21 }],
        25: [function(require, module, exports) {
            var Quoted = require("../tree/quoted"),
                Anonymous = require("../tree/anonymous"),
                JavaScript = require("../tree/javascript"),
                functionRegistry = require("./function-registry");

            functionRegistry.addMultiple({
                e: function(str) {
                    return new Anonymous(str instanceof JavaScript ? str.evaluated : str.value);
                },
                escape: function(str) {
                    return new Anonymous(
                        encodeURI(str.value).replace(/=/g, "%3D").replace(/:/g, "%3A").replace(/#/g, "%23").replace(/;/g, "%3B")
                        .replace(/\(/g, "%28").replace(/\)/g, "%29"));
                },
                replace: function(string, pattern, replacement, flags) {
                    var result = string.value;
                    replacement = (replacement.type === "Quoted") ?
                        replacement.value : replacement.toCSS();
                    result = result.replace(new RegExp(pattern.value, flags ? flags.value : ''), replacement);
                    return new Quoted(string.quote || '', result, string.escaped);
                },
                '%': function(string /* arg, arg, ...*/ ) {
                    var args = Array.prototype.slice.call(arguments, 1),
                        result = string.value;

                    for (var i = 0; i < args.length; i++) {
                        /*jshint loopfunc:true */
                        result = result.replace(/%[sda]/i, function(token) {
                            var value = ((args[i].type === "Quoted") &&
                                token.match(/s/i)) ? args[i].value : args[i].toCSS();
                            return token.match(/[A-Z]$/) ? encodeURIComponent(value) : value;
                        });
                    }
                    result = result.replace(/%%/g, '%');
                    return new Quoted(string.quote || '', result, string.escaped);
                }
            });

        }, { "../tree/anonymous": 44, "../tree/javascript": 61, "../tree/quoted": 71, "./function-registry": 21 }],
        26: [function(require, module, exports) {
            module.exports = function(environment) {
                var Dimension = require("../tree/dimension"),
                    Color = require("../tree/color"),
                    Expression = require("../tree/expression"),
                    Quoted = require("../tree/quoted"),
                    URL = require("../tree/url"),
                    functionRegistry = require("./function-registry");

                functionRegistry.add("svg-gradient", function(direction) {

                    var stops,
                        gradientDirectionSvg,
                        gradientType = "linear",
                        rectangleDimension = 'x="0" y="0" width="1" height="1"',
                        renderEnv = { compress: false },
                        returner,
                        directionValue = direction.toCSS(renderEnv),
                        i, color, position, positionValue, alpha;

                    function throwArgumentDescriptor() {
                        throw {
                            type: "Argument",
                            message: "svg-gradient expects direction, start_color [start_position], [color position,]...," +
                                " end_color [end_position] or direction, color list"
                        };
                    }

                    if (arguments.length == 2) {
                        if (arguments[1].value.length < 2) {
                            throwArgumentDescriptor();
                        }
                        stops = arguments[1].value;
                    } else if (arguments.length < 3) {
                        throwArgumentDescriptor();
                    } else {
                        stops = Array.prototype.slice.call(arguments, 1);
                    }

                    switch (directionValue) {
                        case "to bottom":
                            gradientDirectionSvg = 'x1="0%" y1="0%" x2="0%" y2="100%"';
                            break;
                        case "to right":
                            gradientDirectionSvg = 'x1="0%" y1="0%" x2="100%" y2="0%"';
                            break;
                        case "to bottom right":
                            gradientDirectionSvg = 'x1="0%" y1="0%" x2="100%" y2="100%"';
                            break;
                        case "to top right":
                            gradientDirectionSvg = 'x1="0%" y1="100%" x2="100%" y2="0%"';
                            break;
                        case "ellipse":
                        case "ellipse at center":
                            gradientType = "radial";
                            gradientDirectionSvg = 'cx="50%" cy="50%" r="75%"';
                            rectangleDimension = 'x="-50" y="-50" width="101" height="101"';
                            break;
                        default:
                            throw {
                                type: "Argument",
                                message: "svg-gradient direction must be 'to bottom', 'to right'," +
                                    " 'to bottom right', 'to top right' or 'ellipse at center'"
                            };
                    }
                    returner = '<?xml version="1.0" ?>' +
                        '<svg xmlns="http://www.w3.org/2000/svg" version="1.1" width="100%" height="100%" viewBox="0 0 1 1" preserveAspectRatio="none">' +
                        '<' + gradientType + 'Gradient id="gradient" gradientUnits="userSpaceOnUse" ' + gradientDirectionSvg + '>';

                    for (i = 0; i < stops.length; i += 1) {
                        if (stops[i] instanceof Expression) {
                            color = stops[i].value[0];
                            position = stops[i].value[1];
                        } else {
                            color = stops[i];
                            position = undefined;
                        }

                        if (!(color instanceof Color) || (!((i === 0 || i + 1 === stops.length) && position === undefined) && !(position instanceof Dimension))) {
                            throwArgumentDescriptor();
                        }
                        positionValue = position ? position.toCSS(renderEnv) : i === 0 ? "0%" : "100%";
                        alpha = color.alpha;
                        returner += '<stop offset="' + positionValue + '" stop-color="' + color.toRGB() + '"' + (alpha < 1 ? ' stop-opacity="' + alpha + '"' : '') + '/>';
                    }
                    returner += '</' + gradientType + 'Gradient>' +
                        '<rect ' + rectangleDimension + ' fill="url(#gradient)" /></svg>';

                    returner = encodeURIComponent(returner);

                    returner = "data:image/svg+xml," + returner;
                    return new URL(new Quoted("'" + returner + "'", returner, false, this.index, this.currentFileInfo), this.index, this.currentFileInfo);
                });
            };

        }, { "../tree/color": 48, "../tree/dimension": 54, "../tree/expression": 57, "../tree/quoted": 71, "../tree/url": 78, "./function-registry": 21 }],
        27: [function(require, module, exports) {
            var Keyword = require("../tree/keyword"),
                DetachedRuleset = require("../tree/detached-ruleset"),
                Dimension = require("../tree/dimension"),
                Color = require("../tree/color"),
                Quoted = require("../tree/quoted"),
                Anonymous = require("../tree/anonymous"),
                URL = require("../tree/url"),
                Operation = require("../tree/operation"),
                functionRegistry = require("./function-registry");

            var isa = function(n, Type) {
                    return (n instanceof Type) ? Keyword.True : Keyword.False;
                },
                isunit = function(n, unit) {
                    if (unit === undefined) {
                        throw { type: "Argument", message: "missing the required second argument to isunit." };
                    }
                    unit = typeof unit.value === "string" ? unit.value : unit;
                    if (typeof unit !== "string") {
                        throw { type: "Argument", message: "Second argument to isunit should be a unit or a string." };
                    }
                    return (n instanceof Dimension) && n.unit.is(unit) ? Keyword.True : Keyword.False;
                },
                getItemsFromNode = function(node) {
                    // handle non-array values as an array of length 1
                    // return 'undefined' if index is invalid
                    var items = Array.isArray(node.value) ?
                        node.value : Array(node);

                    return items;
                };
            functionRegistry.addMultiple({
                isruleset: function(n) {
                    return isa(n, DetachedRuleset);
                },
                iscolor: function(n) {
                    return isa(n, Color);
                },
                isnumber: function(n) {
                    return isa(n, Dimension);
                },
                isstring: function(n) {
                    return isa(n, Quoted);
                },
                iskeyword: function(n) {
                    return isa(n, Keyword);
                },
                isurl: function(n) {
                    return isa(n, URL);
                },
                ispixel: function(n) {
                    return isunit(n, 'px');
                },
                ispercentage: function(n) {
                    return isunit(n, '%');
                },
                isem: function(n) {
                    return isunit(n, 'em');
                },
                isunit: isunit,
                unit: function(val, unit) {
                    if (!(val instanceof Dimension)) {
                        throw {
                            type: "Argument",
                            message: "the first argument to unit must be a number" +
                                (val instanceof Operation ? ". Have you forgotten parenthesis?" : "")
                        };
                    }
                    if (unit) {
                        if (unit instanceof Keyword) {
                            unit = unit.value;
                        } else {
                            unit = unit.toCSS();
                        }
                    } else {
                        unit = "";
                    }
                    return new Dimension(val.value, unit);
                },
                "get-unit": function(n) {
                    return new Anonymous(n.unit);
                },
                extract: function(values, index) {
                    index = index.value - 1; // (1-based index)

                    return getItemsFromNode(values)[index];
                },
                length: function(values) {
                    return new Dimension(getItemsFromNode(values).length);
                }
            });

        }, { "../tree/anonymous": 44, "../tree/color": 48, "../tree/detached-ruleset": 53, "../tree/dimension": 54, "../tree/keyword": 63, "../tree/operation": 69, "../tree/quoted": 71, "../tree/url": 78, "./function-registry": 21 }],
        28: [function(require, module, exports) {
            var contexts = require("./contexts"),
                Parser = require('./parser/parser'),
                FunctionImporter = require('./plugins/function-importer');

            module.exports = function(environment) {

                // FileInfo = {
                //  'relativeUrls' - option - whether to adjust URL's to be relative
                //  'filename' - full resolved filename of current file
                //  'rootpath' - path to append to normal URLs for this node
                //  'currentDirectory' - path to the current file, absolute
                //  'rootFilename' - filename of the base file
                //  'entryPath' - absolute path to the entry file
                //  'reference' - whether the file should not be output and only output parts that are referenced

                var ImportManager = function(context, rootFileInfo) {
                    this.rootFilename = rootFileInfo.filename;
                    this.paths = context.paths || []; // Search paths, when importing
                    this.contents = {}; // map - filename to contents of all the files
                    this.contentsIgnoredChars = {}; // map - filename to lines at the beginning of each file to ignore
                    this.mime = context.mime;
                    this.error = null;
                    this.context = context;
                    // Deprecated? Unused outside of here, could be useful.
                    this.queue = []; // Files which haven't been imported yet
                    this.files = {}; // Holds the imported parse trees.
                };
                /**
                 * Add an import to be imported
                 * @param path - the raw path
                 * @param tryAppendLessExtension - whether to try appending the less extension (if the path has no extension)
                 * @param currentFileInfo - the current file info (used for instance to work out relative paths)
                 * @param importOptions - import options
                 * @param callback - callback for when it is imported
                 */
                ImportManager.prototype.push = function(path, tryAppendLessExtension, currentFileInfo, importOptions, callback) {
                    var importManager = this;
                    this.queue.push(path);

                    var fileParsedFunc = function(e, root, fullPath) {
                        importManager.queue.splice(importManager.queue.indexOf(path), 1); // Remove the path from the queue

                        var importedEqualsRoot = fullPath === importManager.rootFilename;
                        if (importOptions.optional && e) {
                            callback(null, { rules: [] }, false, null);
                        } else {
                            importManager.files[fullPath] = root;
                            if (e && !importManager.error) { importManager.error = e; }
                            callback(e, root, importedEqualsRoot, fullPath);
                        }
                    };

                    var newFileInfo = {
                        relativeUrls: this.context.relativeUrls,
                        entryPath: currentFileInfo.entryPath,
                        rootpath: currentFileInfo.rootpath,
                        rootFilename: currentFileInfo.rootFilename
                    };

                    var fileManager = environment.getFileManager(path, currentFileInfo.currentDirectory, this.context, environment);

                    if (!fileManager) {
                        fileParsedFunc({ message: "Could not find a file-manager for " + path });
                        return;
                    }

                    if (tryAppendLessExtension) {
                        path = fileManager.tryAppendExtension(path, importOptions.plugin ? ".js" : ".less");
                    }

                    var loadFileCallback = function(loadedFile) {
                        var resolvedFilename = loadedFile.filename,
                            contents = loadedFile.contents.replace(/^\uFEFF/, '');

                        // Pass on an updated rootpath if path of imported file is relative and file
                        // is in a (sub|sup) directory
                        //
                        // Examples:
                        // - If path of imported file is 'module/nav/nav.less' and rootpath is 'less/',
                        //   then rootpath should become 'less/module/nav/'
                        // - If path of imported file is '../mixins.less' and rootpath is 'less/',
                        //   then rootpath should become 'less/../'
                        newFileInfo.currentDirectory = fileManager.getPath(resolvedFilename);
                        if (newFileInfo.relativeUrls) {
                            newFileInfo.rootpath = fileManager.join(
                                (importManager.context.rootpath || ""),
                                fileManager.pathDiff(newFileInfo.currentDirectory, newFileInfo.entryPath));

                            if (!fileManager.isPathAbsolute(newFileInfo.rootpath) && fileManager.alwaysMakePathsAbsolute()) {
                                newFileInfo.rootpath = fileManager.join(newFileInfo.entryPath, newFileInfo.rootpath);
                            }
                        }
                        newFileInfo.filename = resolvedFilename;

                        var newEnv = new contexts.Parse(importManager.context);

                        newEnv.processImports = false;
                        importManager.contents[resolvedFilename] = contents;

                        if (currentFileInfo.reference || importOptions.reference) {
                            newFileInfo.reference = true;
                        }

                        if (importOptions.plugin) {
                            new FunctionImporter(newEnv, newFileInfo).eval(contents, function(e, root) {
                                fileParsedFunc(e, root, resolvedFilename);
                            });
                        } else if (importOptions.inline) {
                            fileParsedFunc(null, contents, resolvedFilename);
                        } else {
                            new Parser(newEnv, importManager, newFileInfo).parse(contents, function(e, root) {
                                fileParsedFunc(e, root, resolvedFilename);
                            });
                        }
                    };

                    var promise = fileManager.loadFile(path, currentFileInfo.currentDirectory, this.context, environment,
                        function(err, loadedFile) {
                            if (err) {
                                fileParsedFunc(err);
                            } else {
                                loadFileCallback(loadedFile);
                            }
                        });
                    if (promise) {
                        promise.then(loadFileCallback, fileParsedFunc);
                    }
                };
                return ImportManager;
            };

        }, { "./contexts": 10, "./parser/parser": 36, "./plugins/function-importer": 38 }],
        29: [function(require, module, exports) {
            module.exports = function(environment, fileManagers) {
                var SourceMapOutput, SourceMapBuilder, ParseTree, ImportManager, Environment;

                var less = {
                    version: [2, 5, 1],
                    data: require('./data'),
                    tree: require('./tree'),
                    Environment: (Environment = require("./environment/environment")),
                    AbstractFileManager: require("./environment/abstract-file-manager"),
                    environment: (environment = new Environment(environment, fileManagers)),
                    visitors: require('./visitors'),
                    Parser: require('./parser/parser'),
                    functions: require('./functions')(environment),
                    contexts: require("./contexts"),
                    SourceMapOutput: (SourceMapOutput = require('./source-map-output')(environment)),
                    SourceMapBuilder: (SourceMapBuilder = require('./source-map-builder')(SourceMapOutput, environment)),
                    ParseTree: (ParseTree = require('./parse-tree')(SourceMapBuilder)),
                    ImportManager: (ImportManager = require('./import-manager')(environment)),
                    render: require("./render")(environment, ParseTree, ImportManager),
                    parse: require("./parse")(environment, ParseTree, ImportManager),
                    LessError: require('./less-error'),
                    transformTree: require('./transform-tree'),
                    utils: require('./utils'),
                    PluginManager: require('./plugin-manager'),
                    logger: require('./logger')
                };

                return less;
            };

        }, { "./contexts": 10, "./data": 12, "./environment/abstract-file-manager": 14, "./environment/environment": 15, "./functions": 22, "./import-manager": 28, "./less-error": 30, "./logger": 31, "./parse": 33, "./parse-tree": 32, "./parser/parser": 36, "./plugin-manager": 37, "./render": 39, "./source-map-builder": 40, "./source-map-output": 41, "./transform-tree": 42, "./tree": 60, "./utils": 81, "./visitors": 85 }],
        30: [function(require, module, exports) {
            var utils = require("./utils");

            var LessError = module.exports = function LessError(e, importManager, currentFilename) {

                Error.call(this);

                var filename = e.filename || currentFilename;

                if (importManager && filename) {
                    var input = importManager.contents[filename],
                        loc = utils.getLocation(e.index, input),
                        line = loc.line,
                        col = loc.column,
                        callLine = e.call && utils.getLocation(e.call, input).line,
                        lines = input.split('\n');

                    this.type = e.type || 'Syntax';
                    this.filename = filename;
                    this.index = e.index;
                    this.line = typeof line === 'number' ? line + 1 : null;
                    this.callLine = callLine + 1;
                    this.callExtract = lines[callLine];
                    this.column = col;
                    this.extract = [
                        lines[line - 1],
                        lines[line],
                        lines[line + 1]
                    ];
                }
                this.message = e.message;
                this.stack = e.stack;
            };

            if (typeof Object.create === 'undefined') {
                var F = function() {};
                F.prototype = Error.prototype;
                LessError.prototype = new F();
            } else {
                LessError.prototype = Object.create(Error.prototype);
            }

            LessError.prototype.constructor = LessError;

        }, { "./utils": 81 }],
        31: [function(require, module, exports) {
            module.exports = {
                error: function(msg) {
                    this._fireEvent("error", msg);
                },
                warn: function(msg) {
                    this._fireEvent("warn", msg);
                },
                info: function(msg) {
                    this._fireEvent("info", msg);
                },
                debug: function(msg) {
                    this._fireEvent("debug", msg);
                },
                addListener: function(listener) {
                    this._listeners.push(listener);
                },
                removeListener: function(listener) {
                    for (var i = 0; i < this._listeners.length; i++) {
                        if (this._listeners[i] === listener) {
                            this._listeners.splice(i, 1);
                            return;
                        }
                    }
                },
                _fireEvent: function(type, msg) {
                    for (var i = 0; i < this._listeners.length; i++) {
                        var logFunction = this._listeners[i][type];
                        if (logFunction) {
                            logFunction(msg);
                        }
                    }
                },
                _listeners: []
            };

        }, {}],
        32: [function(require, module, exports) {
            var LessError = require('./less-error'),
                transformTree = require("./transform-tree"),
                logger = require("./logger");

            module.exports = function(SourceMapBuilder) {
                var ParseTree = function(root, imports) {
                    this.root = root;
                    this.imports = imports;
                };

                ParseTree.prototype.toCSS = function(options) {
                    var evaldRoot, result = {},
                        sourceMapBuilder;
                    try {
                        evaldRoot = transformTree(this.root, options);
                    } catch (e) {
                        throw new LessError(e, this.imports);
                    }

                    try {
                        var compress = Boolean(options.compress);
                        if (compress) {
                            logger.warn("The compress option has been deprecated. We recommend you use a dedicated css minifier, for instance see less-plugin-clean-css.");
                        }

                        var toCSSOptions = {
                            compress: compress,
                            dumpLineNumbers: options.dumpLineNumbers,
                            strictUnits: Boolean(options.strictUnits),
                            numPrecision: 8
                        };

                        if (options.sourceMap) {
                            sourceMapBuilder = new SourceMapBuilder(options.sourceMap);
                            result.css = sourceMapBuilder.toCSS(evaldRoot, toCSSOptions, this.imports);
                        } else {
                            result.css = evaldRoot.toCSS(toCSSOptions);
                        }
                    } catch (e) {
                        throw new LessError(e, this.imports);
                    }

                    if (options.pluginManager) {
                        var postProcessors = options.pluginManager.getPostProcessors();
                        for (var i = 0; i < postProcessors.length; i++) {
                            result.css = postProcessors[i].process(result.css, { sourceMap: sourceMapBuilder, options: options, imports: this.imports });
                        }
                    }
                    if (options.sourceMap) {
                        result.map = sourceMapBuilder.getExternalSourceMap();
                    }

                    result.imports = [];
                    for (var file in this.imports.files) {
                        if (this.imports.files.hasOwnProperty(file) && file !== this.imports.rootFilename) {
                            result.imports.push(file);
                        }
                    }
                    return result;
                };
                return ParseTree;
            };

        }, { "./less-error": 30, "./logger": 31, "./transform-tree": 42 }],
        33: [function(require, module, exports) {
            var PromiseConstructor,
                contexts = require("./contexts"),
                Parser = require('./parser/parser'),
                PluginManager = require('./plugin-manager');

            module.exports = function(environment, ParseTree, ImportManager) {
                var parse = function(input, options, callback) {
                    options = options || {};

                    if (typeof options === 'function') {
                        callback = options;
                        options = {};
                    }

                    if (!callback) {
                        if (!PromiseConstructor) {
                            PromiseConstructor = typeof Promise === 'undefined' ? require('promise') : Promise;
                        }
                        var self = this;
                        return new PromiseConstructor(function(resolve, reject) {
                            parse.call(self, input, options, function(err, output) {
                                if (err) {
                                    reject(err);
                                } else {
                                    resolve(output);
                                }
                            });
                        });
                    } else {
                        var context,
                            rootFileInfo,
                            pluginManager = new PluginManager(this);

                        pluginManager.addPlugins(options.plugins);
                        options.pluginManager = pluginManager;

                        context = new contexts.Parse(options);

                        if (options.rootFileInfo) {
                            rootFileInfo = options.rootFileInfo;
                        } else {
                            var filename = options.filename || "input";
                            var entryPath = filename.replace(/[^\/\\]*$/, "");
                            rootFileInfo = {
                                filename: filename,
                                relativeUrls: context.relativeUrls,
                                rootpath: context.rootpath || "",
                                currentDirectory: entryPath,
                                entryPath: entryPath,
                                rootFilename: filename
                            };
                            // add in a missing trailing slash
                            if (rootFileInfo.rootpath && rootFileInfo.rootpath.slice(-1) !== "/") {
                                rootFileInfo.rootpath += "/";
                            }
                        }

                        var imports = new ImportManager(context, rootFileInfo);

                        new Parser(context, imports, rootFileInfo)
                            .parse(input, function(e, root) {
                                if (e) { return callback(e); }
                                callback(null, root, imports, options);
                            }, options);
                    }
                };
                return parse;
            };

        }, { "./contexts": 10, "./parser/parser": 36, "./plugin-manager": 37, "promise": undefined }],
        34: [function(require, module, exports) {
            // Split the input into chunks.
            module.exports = function(input, fail) {
                var len = input.length,
                    level = 0,
                    parenLevel = 0,
                    lastOpening, lastOpeningParen, lastMultiComment, lastMultiCommentEndBrace,
                    chunks = [],
                    emitFrom = 0,
                    chunkerCurrentIndex, currentChunkStartIndex, cc, cc2, matched;

                function emitChunk(force) {
                    var len = chunkerCurrentIndex - emitFrom;
                    if (((len < 512) && !force) || !len) {
                        return;
                    }
                    chunks.push(input.slice(emitFrom, chunkerCurrentIndex + 1));
                    emitFrom = chunkerCurrentIndex + 1;
                }

                for (chunkerCurrentIndex = 0; chunkerCurrentIndex < len; chunkerCurrentIndex++) {
                    cc = input.charCodeAt(chunkerCurrentIndex);
                    if (((cc >= 97) && (cc <= 122)) || (cc < 34)) {
                        // a-z or whitespace
                        continue;
                    }

                    switch (cc) {
                        case 40: // (
                            parenLevel++;
                            lastOpeningParen = chunkerCurrentIndex;
                            continue;
                        case 41: // )
                            if (--parenLevel < 0) {
                                return fail("missing opening `(`", chunkerCurrentIndex);
                            }
                            continue;
                        case 59: // ;
                            if (!parenLevel) { emitChunk(); }
                            continue;
                        case 123: // {
                            level++;
                            lastOpening = chunkerCurrentIndex;
                            continue;
                        case 125: // }
                            if (--level < 0) {
                                return fail("missing opening `{`", chunkerCurrentIndex);
                            }
                            if (!level && !parenLevel) { emitChunk(); }
                            continue;
                        case 92: // \
                            if (chunkerCurrentIndex < len - 1) { chunkerCurrentIndex++; continue; }
                            return fail("unescaped `\\`", chunkerCurrentIndex);
                        case 34:
                        case 39:
                        case 96: // ", ' and `
                            matched = 0;
                            currentChunkStartIndex = chunkerCurrentIndex;
                            for (chunkerCurrentIndex = chunkerCurrentIndex + 1; chunkerCurrentIndex < len; chunkerCurrentIndex++) {
                                cc2 = input.charCodeAt(chunkerCurrentIndex);
                                if (cc2 > 96) { continue; }
                                if (cc2 == cc) { matched = 1; break; }
                                if (cc2 == 92) { // \
                                    if (chunkerCurrentIndex == len - 1) {
                                        return fail("unescaped `\\`", chunkerCurrentIndex);
                                    }
                                    chunkerCurrentIndex++;
                                }
                            }
                            if (matched) { continue; }
                            return fail("unmatched `" + String.fromCharCode(cc) + "`", currentChunkStartIndex);
                        case 47: // /, check for comment
                            if (parenLevel || (chunkerCurrentIndex == len - 1)) { continue; }
                            cc2 = input.charCodeAt(chunkerCurrentIndex + 1);
                            if (cc2 == 47) {
                                // //, find lnfeed
                                for (chunkerCurrentIndex = chunkerCurrentIndex + 2; chunkerCurrentIndex < len; chunkerCurrentIndex++) {
                                    cc2 = input.charCodeAt(chunkerCurrentIndex);
                                    if ((cc2 <= 13) && ((cc2 == 10) || (cc2 == 13))) { break; }
                                }
                            } else if (cc2 == 42) {
                                // /*, find */
                                lastMultiComment = currentChunkStartIndex = chunkerCurrentIndex;
                                for (chunkerCurrentIndex = chunkerCurrentIndex + 2; chunkerCurrentIndex < len - 1; chunkerCurrentIndex++) {
                                    cc2 = input.charCodeAt(chunkerCurrentIndex);
                                    if (cc2 == 125) { lastMultiCommentEndBrace = chunkerCurrentIndex; }
                                    if (cc2 != 42) { continue; }
                                    if (input.charCodeAt(chunkerCurrentIndex + 1) == 47) { break; }
                                }
                                if (chunkerCurrentIndex == len - 1) {
                                    return fail("missing closing `*/`", currentChunkStartIndex);
                                }
                                chunkerCurrentIndex++;
                            }
                            continue;
                        case 42: // *, check for unmatched */
                            if ((chunkerCurrentIndex < len - 1) && (input.charCodeAt(chunkerCurrentIndex + 1) == 47)) {
                                return fail("unmatched `/*`", chunkerCurrentIndex);
                            }
                            continue;
                    }
                }

                if (level !== 0) {
                    if ((lastMultiComment > lastOpening) && (lastMultiCommentEndBrace > lastMultiComment)) {
                        return fail("missing closing `}` or `*/`", lastOpening);
                    } else {
                        return fail("missing closing `}`", lastOpening);
                    }
                } else if (parenLevel !== 0) {
                    return fail("missing closing `)`", lastOpeningParen);
                }

                emitChunk(true);
                return chunks;
            };

        }, {}],
        35: [function(require, module, exports) {
            var chunker = require('./chunker');

            module.exports = function() {
                var input, // LeSS input string
                    j, // current chunk
                    saveStack = [], // holds state for backtracking
                    furthest, // furthest index the parser has gone to
                    furthestPossibleErrorMessage, // if this is furthest we got to, this is the probably cause
                    chunks, // chunkified input
                    current, // current chunk
                    currentPos, // index of current chunk, in `input`
                    parserInput = {};

                parserInput.save = function() {
                    currentPos = parserInput.i;
                    saveStack.push({ current: current, i: parserInput.i, j: j });
                };
                parserInput.restore = function(possibleErrorMessage) {

                    if (parserInput.i > furthest || (parserInput.i === furthest && possibleErrorMessage && !furthestPossibleErrorMessage)) {
                        furthest = parserInput.i;
                        furthestPossibleErrorMessage = possibleErrorMessage;
                    }
                    var state = saveStack.pop();
                    current = state.current;
                    currentPos = parserInput.i = state.i;
                    j = state.j;
                };
                parserInput.forget = function() {
                    saveStack.pop();
                };
                parserInput.isWhitespace = function(offset) {
                    var pos = parserInput.i + (offset || 0),
                        code = input.charCodeAt(pos);
                    return (code === CHARCODE_SPACE || code === CHARCODE_CR || code === CHARCODE_TAB || code === CHARCODE_LF);
                };

                // Specialization of $(tok)
                parserInput.$re = function(tok) {
                    if (parserInput.i > currentPos) {
                        current = current.slice(parserInput.i - currentPos);
                        currentPos = parserInput.i;
                    }

                    var m = tok.exec(current);
                    if (!m) {
                        return null;
                    }

                    skipWhitespace(m[0].length);
                    if (typeof m === "string") {
                        return m;
                    }

                    return m.length === 1 ? m[0] : m;
                };

                parserInput.$char = function(tok) {
                    if (input.charAt(parserInput.i) !== tok) {
                        return null;
                    }
                    skipWhitespace(1);
                    return tok;
                };

                parserInput.$str = function(tok) {
                    var tokLength = tok.length;

                    // https://jsperf.com/string-startswith/21
                    for (var i = 0; i < tokLength; i++) {
                        if (input.charAt(parserInput.i + i) !== tok.charAt(i)) {
                            return null;
                        }
                    }

                    skipWhitespace(tokLength);
                    return tok;
                };

                parserInput.$quoted = function() {

                    var startChar = input.charAt(parserInput.i);
                    if (startChar !== "'" && startChar !== '"') {
                        return;
                    }
                    var length = input.length,
                        currentPosition = parserInput.i;

                    for (var i = 1; i + currentPosition < length; i++) {
                        var nextChar = input.charAt(i + currentPosition);
                        switch (nextChar) {
                            case "\\":
                                i++;
                                continue;
                            case "\r":
                            case "\n":
                                break;
                            case startChar:
                                var str = input.substr(currentPosition, i + 1);
                                skipWhitespace(i + 1);
                                return str;
                            default:
                        }
                    }
                    return null;
                };

                var CHARCODE_SPACE = 32,
                    CHARCODE_TAB = 9,
                    CHARCODE_LF = 10,
                    CHARCODE_CR = 13,
                    CHARCODE_PLUS = 43,
                    CHARCODE_COMMA = 44,
                    CHARCODE_FORWARD_SLASH = 47,
                    CHARCODE_9 = 57;

                parserInput.autoCommentAbsorb = true;
                parserInput.commentStore = [];
                parserInput.finished = false;

                var skipWhitespace = function(length) {
                    var oldi = parserInput.i,
                        oldj = j,
                        curr = parserInput.i - currentPos,
                        endIndex = parserInput.i + current.length - curr,
                        mem = (parserInput.i += length),
                        inp = input,
                        c, nextChar, comment;

                    for (; parserInput.i < endIndex; parserInput.i++) {
                        c = inp.charCodeAt(parserInput.i);

                        if (parserInput.autoCommentAbsorb && c === CHARCODE_FORWARD_SLASH) {
                            nextChar = inp.charAt(parserInput.i + 1);
                            if (nextChar === '/') {
                                comment = { index: parserInput.i, isLineComment: true };
                                var nextNewLine = inp.indexOf("\n", parserInput.i + 2);
                                if (nextNewLine < 0) {
                                    nextNewLine = endIndex;
                                }
                                parserInput.i = nextNewLine;
                                comment.text = inp.substr(comment.i, parserInput.i - comment.i);
                                parserInput.commentStore.push(comment);
                                continue;
                            } else if (nextChar === '*') {
                                var nextStarSlash = inp.indexOf("*/", parserInput.i + 2);
                                if (nextStarSlash >= 0) {
                                    comment = {
                                        index: parserInput.i,
                                        text: inp.substr(parserInput.i, nextStarSlash + 2 - parserInput.i),
                                        isLineComment: false
                                    };
                                    parserInput.i += comment.text.length - 1;
                                    parserInput.commentStore.push(comment);
                                    continue;
                                }
                            }
                            break;
                        }

                        if ((c !== CHARCODE_SPACE) && (c !== CHARCODE_LF) && (c !== CHARCODE_TAB) && (c !== CHARCODE_CR)) {
                            break;
                        }
                    }

                    current = current.slice(length + parserInput.i - mem + curr);
                    currentPos = parserInput.i;

                    if (!current.length) {
                        if (j < chunks.length - 1) {
                            current = chunks[++j];
                            skipWhitespace(0); // skip space at the beginning of a chunk
                            return true; // things changed
                        }
                        parserInput.finished = true;
                    }

                    return oldi !== parserInput.i || oldj !== j;
                };

                // Same as $(), but don't change the state of the parser,
                // just return the match.
                parserInput.peek = function(tok) {
                    if (typeof tok === 'string') {
                        // https://jsperf.com/string-startswith/21
                        for (var i = 0; i < tok.length; i++) {
                            if (input.charAt(parserInput.i + i) !== tok.charAt(i)) {
                                return false;
                            }
                        }
                        return true;
                    } else {
                        return tok.test(current);
                    }
                };

                // Specialization of peek()
                // TODO remove or change some currentChar calls to peekChar
                parserInput.peekChar = function(tok) {
                    return input.charAt(parserInput.i) === tok;
                };

                parserInput.currentChar = function() {
                    return input.charAt(parserInput.i);
                };

                parserInput.getInput = function() {
                    return input;
                };

                parserInput.peekNotNumeric = function() {
                    var c = input.charCodeAt(parserInput.i);
                    //Is the first char of the dimension 0-9, '.', '+' or '-'
                    return (c > CHARCODE_9 || c < CHARCODE_PLUS) || c === CHARCODE_FORWARD_SLASH || c === CHARCODE_COMMA;
                };

                parserInput.start = function(str, chunkInput, failFunction) {
                    input = str;
                    parserInput.i = j = currentPos = furthest = 0;

                    // chunking apparantly makes things quicker (but my tests indicate
                    // it might actually make things slower in node at least)
                    // and it is a non-perfect parse - it can't recognise
                    // unquoted urls, meaning it can't distinguish comments
                    // meaning comments with quotes or {}() in them get 'counted'
                    // and then lead to parse errors.
                    // In addition if the chunking chunks in the wrong place we might
                    // not be able to parse a parser statement in one go
                    // this is officially deprecated but can be switched on via an option
                    // in the case it causes too much performance issues.
                    if (chunkInput) {
                        chunks = chunker(str, failFunction);
                    } else {
                        chunks = [str];
                    }

                    current = chunks[0];

                    skipWhitespace(0);
                };

                parserInput.end = function() {
                    var message,
                        isFinished = parserInput.i >= input.length;

                    if (parserInput.i < furthest) {
                        message = furthestPossibleErrorMessage;
                        parserInput.i = furthest;
                    }
                    return {
                        isFinished: isFinished,
                        furthest: parserInput.i,
                        furthestPossibleErrorMessage: message,
                        furthestReachedEnd: parserInput.i >= input.length - 1,
                        furthestChar: input[parserInput.i]
                    };
                };

                return parserInput;
            };

        }, { "./chunker": 34 }],
        36: [function(require, module, exports) {
            var LessError = require('../less-error'),
                tree = require("../tree"),
                visitors = require("../visitors"),
                getParserInput = require("./parser-input"),
                utils = require("../utils");

            //
            // less.js - parser
            //
            //    A relatively straight-forward predictive parser.
            //    There is no tokenization/lexing stage, the input is parsed
            //    in one sweep.
            //
            //    To make the parser fast enough to run in the browser, several
            //    optimization had to be made:
            //
            //    - Matching and slicing on a huge input is often cause of slowdowns.
            //      The solution is to chunkify the input into smaller strings.
            //      The chunks are stored in the `chunks` var,
            //      `j` holds the current chunk index, and `currentPos` holds
            //      the index of the current chunk in relation to `input`.
            //      This gives us an almost 4x speed-up.
            //
            //    - In many cases, we don't need to match individual tokens;
            //      for example, if a value doesn't hold any variables, operations
            //      or dynamic references, the parser can effectively 'skip' it,
            //      treating it as a literal.
            //      An example would be '1px solid #000' - which evaluates to itself,
            //      we don't need to know what the individual components are.
            //      The drawback, of course is that you don't get the benefits of
            //      syntax-checking on the CSS. This gives us a 50% speed-up in the parser,
            //      and a smaller speed-up in the code-gen.
            //
            //
            //    Token matching is done with the `$` function, which either takes
            //    a terminal string or regexp, or a non-terminal function to call.
            //    It also takes care of moving all the indices forwards.
            //
            //
            var Parser = function Parser(context, imports, fileInfo) {
                var parsers,
                    parserInput = getParserInput();

                function expect(arg, msg, index) {
                    // some older browsers return typeof 'function' for RegExp
                    var result = (Object.prototype.toString.call(arg) === '[object Function]') ? arg.call(parsers) : parserInput.$re(arg);
                    if (result) {
                        return result;
                    }
                    error(msg || (typeof arg === 'string' ? "expected '" + arg + "' got '" + parserInput.currentChar() + "'" :
                        "unexpected token"));
                }

                // Specialization of expect()
                function expectChar(arg, msg) {
                    if (parserInput.$char(arg)) {
                        return arg;
                    }
                    error(msg || "expected '" + arg + "' got '" + parserInput.currentChar() + "'");
                }

                function error(msg, type) {
                    throw new LessError({
                            index: parserInput.i,
                            filename: fileInfo.filename,
                            type: type || 'Syntax',
                            message: msg
                        },
                        imports
                    );
                }

                function getDebugInfo(index) {
                    var filename = fileInfo.filename;

                    return {
                        lineNumber: utils.getLocation(index, parserInput.getInput()).line + 1,
                        fileName: filename
                    };
                }

                //
                // The Parser
                //
                return {

                    //
                    // Parse an input string into an abstract syntax tree,
                    // @param str A string containing 'less' markup
                    // @param callback call `callback` when done.
                    // @param [additionalData] An optional map which can contains vars - a map (key, value) of variables to apply
                    //
                    parse: function(str, callback, additionalData) {
                        var root, error = null,
                            globalVars, modifyVars, ignored, preText = "";

                        globalVars = (additionalData && additionalData.globalVars) ? Parser.serializeVars(additionalData.globalVars) + '\n' : '';
                        modifyVars = (additionalData && additionalData.modifyVars) ? '\n' + Parser.serializeVars(additionalData.modifyVars) : '';

                        if (context.pluginManager) {
                            var preProcessors = context.pluginManager.getPreProcessors();
                            for (var i = 0; i < preProcessors.length; i++) {
                                str = preProcessors[i].process(str, { context: context, imports: imports, fileInfo: fileInfo });
                            }
                        }

                        if (globalVars || (additionalData && additionalData.banner)) {
                            preText = ((additionalData && additionalData.banner) ? additionalData.banner : "") + globalVars;
                            ignored = imports.contentsIgnoredChars;
                            ignored[fileInfo.filename] = ignored[fileInfo.filename] || 0;
                            ignored[fileInfo.filename] += preText.length;
                        }

                        str = str.replace(/\r\n?/g, '\n');
                        // Remove potential UTF Byte Order Mark
                        str = preText + str.replace(/^\uFEFF/, '') + modifyVars;
                        imports.contents[fileInfo.filename] = str;

                        // Start with the primary rule.
                        // The whole syntax tree is held under a Ruleset node,
                        // with the `root` property set to true, so no `{}` are
                        // output. The callback is called when the input is parsed.
                        try {
                            parserInput.start(str, context.chunkInput, function fail(msg, index) {
                                throw new LessError({
                                    index: index,
                                    type: 'Parse',
                                    message: msg,
                                    filename: fileInfo.filename
                                }, imports);
                            });

                            root = new(tree.Ruleset)(null, this.parsers.primary());
                            root.root = true;
                            root.firstRoot = true;
                        } catch (e) {
                            return callback(new LessError(e, imports, fileInfo.filename));
                        }

                        // If `i` is smaller than the `input.length - 1`,
                        // it means the parser wasn't able to parse the whole
                        // string, so we've got a parsing error.
                        //
                        // We try to extract a \n delimited string,
                        // showing the line where the parse error occurred.
                        // We split it up into two parts (the part which parsed,
                        // and the part which didn't), so we can color them differently.
                        var endInfo = parserInput.end();
                        if (!endInfo.isFinished) {

                            var message = endInfo.furthestPossibleErrorMessage;

                            if (!message) {
                                message = "Unrecognised input";
                                if (endInfo.furthestChar === '}') {
                                    message += ". Possibly missing opening '{'";
                                } else if (endInfo.furthestChar === ')') {
                                    message += ". Possibly missing opening '('";
                                } else if (endInfo.furthestReachedEnd) {
                                    message += ". Possibly missing something";
                                }
                            }

                            error = new LessError({
                                type: "Parse",
                                message: message,
                                index: endInfo.furthest,
                                filename: fileInfo.filename
                            }, imports);
                        }

                        var finish = function(e) {
                            e = error || e || imports.error;

                            if (e) {
                                if (!(e instanceof LessError)) {
                                    e = new LessError(e, imports, fileInfo.filename);
                                }

                                return callback(e);
                            } else {
                                return callback(null, root);
                            }
                        };

                        if (context.processImports !== false) {
                            new visitors.ImportVisitor(imports, finish)
                                .run(root);
                        } else {
                            return finish();
                        }
                    },

                    //
                    // Here in, the parsing rules/functions
                    //
                    // The basic structure of the syntax tree generated is as follows:
                    //
                    //   Ruleset ->  Rule -> Value -> Expression -> Entity
                    //
                    // Here's some Less code:
                    //
                    //    .class {
                    //      color: #fff;
                    //      border: 1px solid #000;
                    //      width: @w + 4px;
                    //      > .child {...}
                    //    }
                    //
                    // And here's what the parse tree might look like:
                    //
                    //     Ruleset (Selector '.class', [
                    //         Rule ("color",  Value ([Expression [Color #fff]]))
                    //         Rule ("border", Value ([Expression [Dimension 1px][Keyword "solid"][Color #000]]))
                    //         Rule ("width",  Value ([Expression [Operation " + " [Variable "@w"][Dimension 4px]]]))
                    //         Ruleset (Selector [Element '>', '.child'], [...])
                    //     ])
                    //
                    //  In general, most rules will try to parse a token with the `$re()` function, and if the return
                    //  value is truly, will return a new node, of the relevant type. Sometimes, we need to check
                    //  first, before parsing, that's when we use `peek()`.
                    //
                    parsers: parsers = {
                        //
                        // The `primary` rule is the *entry* and *exit* point of the parser.
                        // The rules here can appear at any level of the parse tree.
                        //
                        // The recursive nature of the grammar is an interplay between the `block`
                        // rule, which represents `{ ... }`, the `ruleset` rule, and this `primary` rule,
                        // as represented by this simplified grammar:
                        //
                        //     primary  →  (ruleset | rule)+
                        //     ruleset  →  selector+ block
                        //     block    →  '{' primary '}'
                        //
                        // Only at one point is the primary rule not called from the
                        // block rule: at the root level.
                        //
                        primary: function() {
                            var mixin = this.mixin,
                                root = [],
                                node;

                            while (true) {
                                while (true) {
                                    node = this.comment();
                                    if (!node) { break; }
                                    root.push(node);
                                }
                                // always process comments before deciding if finished
                                if (parserInput.finished) {
                                    break;
                                }
                                if (parserInput.peek('}')) {
                                    break;
                                }

                                node = this.extendRule();
                                if (node) {
                                    root = root.concat(node);
                                    continue;
                                }

                                node = mixin.definition() || this.rule() || this.ruleset() ||
                                    mixin.call() || this.rulesetCall() || this.directive();
                                if (node) {
                                    root.push(node);
                                } else {
                                    var foundSemiColon = false;
                                    while (parserInput.$char(";")) {
                                        foundSemiColon = true;
                                    }
                                    if (!foundSemiColon) {
                                        break;
                                    }
                                }
                            }

                            return root;
                        },

                        // comments are collected by the main parsing mechanism and then assigned to nodes
                        // where the current structure allows it
                        comment: function() {
                            if (parserInput.commentStore.length) {
                                var comment = parserInput.commentStore.shift();
                                return new(tree.Comment)(comment.text, comment.isLineComment, comment.index, fileInfo);
                            }
                        },

                        //
                        // Entities are tokens which can be found inside an Expression
                        //
                        entities: {
                            //
                            // A string, which supports escaping " and '
                            //
                            //     "milky way" 'he\'s the one!'
                            //
                            quoted: function() {
                                var str, index = parserInput.i,
                                    isEscaped = false;

                                parserInput.save();
                                if (parserInput.$char("~")) {
                                    isEscaped = true;
                                }
                                str = parserInput.$quoted();
                                if (!str) {
                                    parserInput.restore();
                                    return;
                                }
                                parserInput.forget();

                                return new(tree.Quoted)(str.charAt(0), str.substr(1, str.length - 2), isEscaped, index, fileInfo);
                            },

                            //
                            // A catch-all word, such as:
                            //
                            //     black border-collapse
                            //
                            keyword: function() {
                                var k = parserInput.$char("%") || parserInput.$re(/^[_A-Za-z-][_A-Za-z0-9-]*/);
                                if (k) {
                                    return tree.Color.fromKeyword(k) || new(tree.Keyword)(k);
                                }
                            },

                            //
                            // A function call
                            //
                            //     rgb(255, 0, 255)
                            //
                            // We also try to catch IE's `alpha()`, but let the `alpha` parser
                            // deal with the details.
                            //
                            // The arguments are parsed with the `entities.arguments` parser.
                            //
                            call: function() {
                                var name, nameLC, args, alpha, index = parserInput.i;

                                // http://jsperf.com/case-insensitive-regex-vs-strtolower-then-regex/18
                                if (parserInput.peek(/^url\(/i)) {
                                    return;
                                }

                                parserInput.save();

                                name = parserInput.$re(/^([\w-]+|%|progid:[\w\.]+)\(/);
                                if (!name) { parserInput.forget(); return; }

                                name = name[1];
                                nameLC = name.toLowerCase();

                                if (nameLC === 'alpha') {
                                    alpha = parsers.alpha();
                                    if (alpha) {
                                        parserInput.forget();
                                        return alpha;
                                    }
                                }

                                args = this.arguments();

                                if (!parserInput.$char(')')) {
                                    parserInput.restore("Could not parse call arguments or missing ')'");
                                    return;
                                }

                                parserInput.forget();
                                return new(tree.Call)(name, args, index, fileInfo);
                            },
                            arguments: function() {
                                var args = [],
                                    arg;

                                while (true) {
                                    arg = this.assignment() || parsers.expression();
                                    if (!arg) {
                                        break;
                                    }
                                    args.push(arg);
                                    if (!parserInput.$char(',')) {
                                        break;
                                    }
                                }
                                return args;
                            },
                            literal: function() {
                                return this.dimension() ||
                                    this.color() ||
                                    this.quoted() ||
                                    this.unicodeDescriptor();
                            },

                            // Assignments are argument entities for calls.
                            // They are present in ie filter properties as shown below.
                            //
                            //     filter: progid:DXImageTransform.Microsoft.Alpha( *opacity=50* )
                            //

                            assignment: function() {
                                var key, value;
                                parserInput.save();
                                key = parserInput.$re(/^\w+(?=\s?=)/i);
                                if (!key) {
                                    parserInput.restore();
                                    return;
                                }
                                if (!parserInput.$char('=')) {
                                    parserInput.restore();
                                    return;
                                }
                                value = parsers.entity();
                                if (value) {
                                    parserInput.forget();
                                    return new(tree.Assignment)(key, value);
                                } else {
                                    parserInput.restore();
                                }
                            },

                            //
                            // Parse url() tokens
                            //
                            // We use a specific rule for urls, because they don't really behave like
                            // standard function calls. The difference is that the argument doesn't have
                            // to be enclosed within a string, so it can't be parsed as an Expression.
                            //
                            url: function() {
                                var value, index = parserInput.i;

                                parserInput.autoCommentAbsorb = false;

                                if (!parserInput.$str("url(")) {
                                    parserInput.autoCommentAbsorb = true;
                                    return;
                                }

                                value = this.quoted() || this.variable() ||
                                    parserInput.$re(/^(?:(?:\\[\(\)'"])|[^\(\)'"])+/) || "";

                                parserInput.autoCommentAbsorb = true;

                                expectChar(')');

                                return new(tree.URL)((value.value != null || value instanceof tree.Variable) ?
                                    value : new(tree.Anonymous)(value), index, fileInfo);
                            },

                            //
                            // A Variable entity, such as `@fink`, in
                            //
                            //     width: @fink + 2px
                            //
                            // We use a different parser for variable definitions,
                            // see `parsers.variable`.
                            //
                            variable: function() {
                                var name, index = parserInput.i;

                                if (parserInput.currentChar() === '@' && (name = parserInput.$re(/^@@?[\w-]+/))) {
                                    return new(tree.Variable)(name, index, fileInfo);
                                }
                            },

                            // A variable entity useing the protective {} e.g. @{var}
                            variableCurly: function() {
                                var curly, index = parserInput.i;

                                if (parserInput.currentChar() === '@' && (curly = parserInput.$re(/^@\{([\w-]+)\}/))) {
                                    return new(tree.Variable)("@" + curly[1], index, fileInfo);
                                }
                            },

                            //
                            // A Hexadecimal color
                            //
                            //     #4F3C2F
                            //
                            // `rgb` and `hsl` colors are parsed through the `entities.call` parser.
                            //
                            color: function() {
                                var rgb;

                                if (parserInput.currentChar() === '#' && (rgb = parserInput.$re(/^#([A-Fa-f0-9]{6}|[A-Fa-f0-9]{3})/))) {
                                    // strip colons, brackets, whitespaces and other characters that should not
                                    // definitely be part of color string
                                    var colorCandidateString = rgb.input.match(/^#([\w]+).*/);
                                    colorCandidateString = colorCandidateString[1];
                                    if (!colorCandidateString.match(/^[A-Fa-f0-9]+$/)) { // verify if candidate consists only of allowed HEX characters
                                        error("Invalid HEX color code");
                                    }
                                    return new(tree.Color)(rgb[1]);
                                }
                            },

                            //
                            // A Dimension, that is, a number and a unit
                            //
                            //     0.5em 95%
                            //
                            dimension: function() {
                                if (parserInput.peekNotNumeric()) {
                                    return;
                                }

                                var value = parserInput.$re(/^([+-]?\d*\.?\d+)(%|[a-z]+)?/i);
                                if (value) {
                                    return new(tree.Dimension)(value[1], value[2]);
                                }
                            },

                            //
                            // A unicode descriptor, as is used in unicode-range
                            //
                            // U+0??  or U+00A1-00A9
                            //
                            unicodeDescriptor: function() {
                                var ud;

                                ud = parserInput.$re(/^U\+[0-9a-fA-F?]+(\-[0-9a-fA-F?]+)?/);
                                if (ud) {
                                    return new(tree.UnicodeDescriptor)(ud[0]);
                                }
                            },

                            //
                            // JavaScript code to be evaluated
                            //
                            //     `window.location.href`
                            //
                            javascript: function() {
                                var js, index = parserInput.i;

                                parserInput.save();

                                var escape = parserInput.$char("~");
                                var jsQuote = parserInput.$char("`");

                                if (!jsQuote) {
                                    parserInput.restore();
                                    return;
                                }

                                js = parserInput.$re(/^[^`]*`/);
                                if (js) {
                                    parserInput.forget();
                                    return new(tree.JavaScript)(js.substr(0, js.length - 1), Boolean(escape), index, fileInfo);
                                }
                                parserInput.restore("invalid javascript definition");
                            }
                        },

                        //
                        // The variable part of a variable definition. Used in the `rule` parser
                        //
                        //     @fink:
                        //
                        variable: function() {
                            var name;

                            if (parserInput.currentChar() === '@' && (name = parserInput.$re(/^(@[\w-]+)\s*:/))) { return name[1]; }
                        },

                        //
                        // The variable part of a variable definition. Used in the `rule` parser
                        //
                        //     @fink();
                        //
                        rulesetCall: function() {
                            var name;

                            if (parserInput.currentChar() === '@' && (name = parserInput.$re(/^(@[\w-]+)\s*\(\s*\)\s*;/))) {
                                return new tree.RulesetCall(name[1]);
                            }
                        },

                        //
                        // extend syntax - used to extend selectors
                        //
                        extend: function(isRule) {
                            var elements, e, index = parserInput.i,
                                option, extendList, extend;

                            if (!parserInput.$str(isRule ? "&:extend(" : ":extend(")) {
                                return;
                            }

                            do {
                                option = null;
                                elements = null;
                                while (!(option = parserInput.$re(/^(all)(?=\s*(\)|,))/))) {
                                    e = this.element();
                                    if (!e) {
                                        break;
                                    }
                                    if (elements) {
                                        elements.push(e);
                                    } else {
                                        elements = [e];
                                    }
                                }

                                option = option && option[1];
                                if (!elements) {
                                    error("Missing target selector for :extend().");
                                }
                                extend = new(tree.Extend)(new(tree.Selector)(elements), option, index);
                                if (extendList) {
                                    extendList.push(extend);
                                } else {
                                    extendList = [extend];
                                }
                            } while (parserInput.$char(","));

                            expect(/^\)/);

                            if (isRule) {
                                expect(/^;/);
                            }

                            return extendList;
                        },

                        //
                        // extendRule - used in a rule to extend all the parent selectors
                        //
                        extendRule: function() {
                            return this.extend(true);
                        },

                        //
                        // Mixins
                        //
                        mixin: {
                            //
                            // A Mixin call, with an optional argument list
                            //
                            //     #mixins > .square(#fff);
                            //     .rounded(4px, black);
                            //     .button;
                            //
                            // The `while` loop is there because mixins can be
                            // namespaced, but we only support the child and descendant
                            // selector for now.
                            //
                            call: function() {
                                var s = parserInput.currentChar(),
                                    important = false,
                                    index = parserInput.i,
                                    elemIndex,
                                    elements, elem, e, c, args;

                                if (s !== '.' && s !== '#') { return; }

                                parserInput.save(); // stop us absorbing part of an invalid selector

                                while (true) {
                                    elemIndex = parserInput.i;
                                    e = parserInput.$re(/^[#.](?:[\w-]|\\(?:[A-Fa-f0-9]{1,6} ?|[^A-Fa-f0-9]))+/);
                                    if (!e) {
                                        break;
                                    }
                                    elem = new(tree.Element)(c, e, elemIndex, fileInfo);
                                    if (elements) {
                                        elements.push(elem);
                                    } else {
                                        elements = [elem];
                                    }
                                    c = parserInput.$char('>');
                                }

                                if (elements) {
                                    if (parserInput.$char('(')) {
                                        args = this.args(true).args;
                                        expectChar(')');
                                    }

                                    if (parsers.important()) {
                                        important = true;
                                    }

                                    if (parsers.end()) {
                                        parserInput.forget();
                                        return new(tree.mixin.Call)(elements, args, index, fileInfo, important);
                                    }
                                }

                                parserInput.restore();
                            },
                            args: function(isCall) {
                                var entities = parsers.entities,
                                    returner = { args: null, variadic: false },
                                    expressions = [],
                                    argsSemiColon = [],
                                    argsComma = [],
                                    isSemiColonSeparated, expressionContainsNamed, name, nameLoop, value, arg;

                                parserInput.save();

                                while (true) {
                                    if (isCall) {
                                        arg = parsers.detachedRuleset() || parsers.expression();
                                    } else {
                                        parserInput.commentStore.length = 0;
                                        if (parserInput.$str("...")) {
                                            returner.variadic = true;
                                            if (parserInput.$char(";") && !isSemiColonSeparated) {
                                                isSemiColonSeparated = true;
                                            }
                                            (isSemiColonSeparated ? argsSemiColon : argsComma)
                                            .push({ variadic: true });
                                            break;
                                        }
                                        arg = entities.variable() || entities.literal() || entities.keyword();
                                    }

                                    if (!arg) {
                                        break;
                                    }

                                    nameLoop = null;
                                    if (arg.throwAwayComments) {
                                        arg.throwAwayComments();
                                    }
                                    value = arg;
                                    var val = null;

                                    if (isCall) {
                                        // Variable
                                        if (arg.value && arg.value.length == 1) {
                                            val = arg.value[0];
                                        }
                                    } else {
                                        val = arg;
                                    }

                                    if (val && val instanceof tree.Variable) {
                                        if (parserInput.$char(':')) {
                                            if (expressions.length > 0) {
                                                if (isSemiColonSeparated) {
                                                    error("Cannot mix ; and , as delimiter types");
                                                }
                                                expressionContainsNamed = true;
                                            }

                                            value = parsers.detachedRuleset() || parsers.expression();

                                            if (!value) {
                                                if (isCall) {
                                                    error("could not understand value for named argument");
                                                } else {
                                                    parserInput.restore();
                                                    returner.args = [];
                                                    return returner;
                                                }
                                            }
                                            nameLoop = (name = val.name);
                                        } else if (!isCall && parserInput.$str("...")) {
                                            returner.variadic = true;
                                            if (parserInput.$char(";") && !isSemiColonSeparated) {
                                                isSemiColonSeparated = true;
                                            }
                                            (isSemiColonSeparated ? argsSemiColon : argsComma)
                                            .push({ name: arg.name, variadic: true });
                                            break;
                                        } else if (!isCall) {
                                            name = nameLoop = val.name;
                                            value = null;
                                        }
                                    }

                                    if (value) {
                                        expressions.push(value);
                                    }

                                    argsComma.push({ name: nameLoop, value: value });

                                    if (parserInput.$char(',')) {
                                        continue;
                                    }

                                    if (parserInput.$char(';') || isSemiColonSeparated) {

                                        if (expressionContainsNamed) {
                                            error("Cannot mix ; and , as delimiter types");
                                        }

                                        isSemiColonSeparated = true;

                                        if (expressions.length > 1) {
                                            value = new(tree.Value)(expressions);
                                        }
                                        argsSemiColon.push({ name: name, value: value });

                                        name = null;
                                        expressions = [];
                                        expressionContainsNamed = false;
                                    }
                                }

                                parserInput.forget();
                                returner.args = isSemiColonSeparated ? argsSemiColon : argsComma;
                                return returner;
                            },
                            //
                            // A Mixin definition, with a list of parameters
                            //
                            //     .rounded (@radius: 2px, @color) {
                            //        ...
                            //     }
                            //
                            // Until we have a finer grained state-machine, we have to
                            // do a look-ahead, to make sure we don't have a mixin call.
                            // See the `rule` function for more information.
                            //
                            // We start by matching `.rounded (`, and then proceed on to
                            // the argument list, which has optional default values.
                            // We store the parameters in `params`, with a `value` key,
                            // if there is a value, such as in the case of `@radius`.
                            //
                            // Once we've got our params list, and a closing `)`, we parse
                            // the `{...}` block.
                            //
                            definition: function() {
                                var name, params = [],
                                    match, ruleset, cond, variadic = false;
                                if ((parserInput.currentChar() !== '.' && parserInput.currentChar() !== '#') ||
                                    parserInput.peek(/^[^{]*\}/)) {
                                    return;
                                }

                                parserInput.save();

                                match = parserInput.$re(/^([#.](?:[\w-]|\\(?:[A-Fa-f0-9]{1,6} ?|[^A-Fa-f0-9]))+)\s*\(/);
                                if (match) {
                                    name = match[1];

                                    var argInfo = this.args(false);
                                    params = argInfo.args;
                                    variadic = argInfo.variadic;

                                    // .mixincall("@{a}");
                                    // looks a bit like a mixin definition..
                                    // also
                                    // .mixincall(@a: {rule: set;});
                                    // so we have to be nice and restore
                                    if (!parserInput.$char(')')) {
                                        parserInput.restore("Missing closing ')'");
                                        return;
                                    }

                                    parserInput.commentStore.length = 0;

                                    if (parserInput.$str("when")) { // Guard
                                        cond = expect(parsers.conditions, 'expected condition');
                                    }

                                    ruleset = parsers.block();

                                    if (ruleset) {
                                        parserInput.forget();
                                        return new(tree.mixin.Definition)(name, params, ruleset, cond, variadic);
                                    } else {
                                        parserInput.restore();
                                    }
                                } else {
                                    parserInput.forget();
                                }
                            }
                        },

                        //
                        // Entities are the smallest recognized token,
                        // and can be found inside a rule's value.
                        //
                        entity: function() {
                            var entities = this.entities;

                            return this.comment() || entities.literal() || entities.variable() || entities.url() ||
                                entities.call() || entities.keyword() || entities.javascript();
                        },

                        //
                        // A Rule terminator. Note that we use `peek()` to check for '}',
                        // because the `block` rule will be expecting it, but we still need to make sure
                        // it's there, if ';' was ommitted.
                        //
                        end: function() {
                            return parserInput.$char(';') || parserInput.peek('}');
                        },

                        //
                        // IE's alpha function
                        //
                        //     alpha(opacity=88)
                        //
                        alpha: function() {
                            var value;

                            // http://jsperf.com/case-insensitive-regex-vs-strtolower-then-regex/18
                            if (!parserInput.$re(/^opacity=/i)) { return; }
                            value = parserInput.$re(/^\d+/);
                            if (!value) {
                                value = expect(this.entities.variable, "Could not parse alpha");
                            }
                            expectChar(')');
                            return new(tree.Alpha)(value);
                        },

                        //
                        // A Selector Element
                        //
                        //     div
                        //     + h1
                        //     #socks
                        //     input[type="text"]
                        //
                        // Elements are the building blocks for Selectors,
                        // they are made out of a `Combinator` (see combinator rule),
                        // and an element name, such as a tag a class, or `*`.
                        //
                        element: function() {
                            var e, c, v, index = parserInput.i;

                            c = this.combinator();

                            e = parserInput.$re(/^(?:\d+\.\d+|\d+)%/) ||
                                parserInput.$re(/^(?:[.#]?|:*)(?:[\w-]|[^\x00-\x9f]|\\(?:[A-Fa-f0-9]{1,6} ?|[^A-Fa-f0-9]))+/) ||
                                parserInput.$char('*') || parserInput.$char('&') || this.attribute() ||
                                parserInput.$re(/^\([^&()@]+\)/) || parserInput.$re(/^[\.#:](?=@)/) ||
                                this.entities.variableCurly();

                            if (!e) {
                                parserInput.save();
                                if (parserInput.$char('(')) {
                                    if ((v = this.selector()) && parserInput.$char(')')) {
                                        e = new(tree.Paren)(v);
                                        parserInput.forget();
                                    } else {
                                        parserInput.restore("Missing closing ')'");
                                    }
                                } else {
                                    parserInput.forget();
                                }
                            }

                            if (e) { return new(tree.Element)(c, e, index, fileInfo); }
                        },

                        //
                        // Combinators combine elements together, in a Selector.
                        //
                        // Because our parser isn't white-space sensitive, special care
                        // has to be taken, when parsing the descendant combinator, ` `,
                        // as it's an empty space. We have to check the previous character
                        // in the input, to see if it's a ` ` character. More info on how
                        // we deal with this in *combinator.js*.
                        //
                        combinator: function() {
                            var c = parserInput.currentChar();

                            if (c === '/') {
                                parserInput.save();
                                var slashedCombinator = parserInput.$re(/^\/[a-z]+\//i);
                                if (slashedCombinator) {
                                    parserInput.forget();
                                    return new(tree.Combinator)(slashedCombinator);
                                }
                                parserInput.restore();
                            }

                            if (c === '>' || c === '+' || c === '~' || c === '|' || c === '^') {
                                parserInput.i++;
                                if (c === '^' && parserInput.currentChar() === '^') {
                                    c = '^^';
                                    parserInput.i++;
                                }
                                while (parserInput.isWhitespace()) { parserInput.i++; }
                                return new(tree.Combinator)(c);
                            } else if (parserInput.isWhitespace(-1)) {
                                return new(tree.Combinator)(" ");
                            } else {
                                return new(tree.Combinator)(null);
                            }
                        },
                        //
                        // A CSS selector (see selector below)
                        // with less extensions e.g. the ability to extend and guard
                        //
                        lessSelector: function() {
                            return this.selector(true);
                        },
                        //
                        // A CSS Selector
                        //
                        //     .class > div + h1
                        //     li a:hover
                        //
                        // Selectors are made out of one or more Elements, see above.
                        //
                        selector: function(isLess) {
                            var index = parserInput.i,
                                elements, extendList, c, e, allExtends, when, condition;

                            while ((isLess && (extendList = this.extend())) || (isLess && (when = parserInput.$str("when"))) || (e = this.element())) {
                                if (when) {
                                    condition = expect(this.conditions, 'expected condition');
                                } else if (condition) {
                                    error("CSS guard can only be used at the end of selector");
                                } else if (extendList) {
                                    if (allExtends) {
                                        allExtends = allExtends.concat(extendList);
                                    } else {
                                        allExtends = extendList;
                                    }
                                } else {
                                    if (allExtends) { error("Extend can only be used at the end of selector"); }
                                    c = parserInput.currentChar();
                                    if (elements) {
                                        elements.push(e);
                                    } else {
                                        elements = [e];
                                    }
                                    e = null;
                                }
                                if (c === '{' || c === '}' || c === ';' || c === ',' || c === ')') {
                                    break;
                                }
                            }

                            if (elements) { return new(tree.Selector)(elements, allExtends, condition, index, fileInfo); }
                            if (allExtends) { error("Extend must be used to extend a selector, it cannot be used on its own"); }
                        },
                        attribute: function() {
                            if (!parserInput.$char('[')) { return; }

                            var entities = this.entities,
                                key, val, op;

                            if (!(key = entities.variableCurly())) {
                                key = expect(/^(?:[_A-Za-z0-9-\*]*\|)?(?:[_A-Za-z0-9-]|\\.)+/);
                            }

                            op = parserInput.$re(/^[|~*$^]?=/);
                            if (op) {
                                val = entities.quoted() || parserInput.$re(/^[0-9]+%/) || parserInput.$re(/^[\w-]+/) || entities.variableCurly();
                            }

                            expectChar(']');

                            return new(tree.Attribute)(key, op, val);
                        },

                        //
                        // The `block` rule is used by `ruleset` and `mixin.definition`.
                        // It's a wrapper around the `primary` rule, with added `{}`.
                        //
                        block: function() {
                            var content;
                            if (parserInput.$char('{') && (content = this.primary()) && parserInput.$char('}')) {
                                return content;
                            }
                        },

                        blockRuleset: function() {
                            var block = this.block();

                            if (block) {
                                block = new tree.Ruleset(null, block);
                            }
                            return block;
                        },

                        detachedRuleset: function() {
                            var blockRuleset = this.blockRuleset();
                            if (blockRuleset) {
                                return new tree.DetachedRuleset(blockRuleset);
                            }
                        },

                        //
                        // div, .class, body > p {...}
                        //
                        ruleset: function() {
                            var selectors, s, rules, debugInfo;

                            parserInput.save();

                            if (context.dumpLineNumbers) {
                                debugInfo = getDebugInfo(parserInput.i);
                            }

                            while (true) {
                                s = this.lessSelector();
                                if (!s) {
                                    break;
                                }
                                if (selectors) {
                                    selectors.push(s);
                                } else {
                                    selectors = [s];
                                }
                                parserInput.commentStore.length = 0;
                                if (s.condition && selectors.length > 1) {
                                    error("Guards are only currently allowed on a single selector.");
                                }
                                if (!parserInput.$char(',')) { break; }
                                if (s.condition) {
                                    error("Guards are only currently allowed on a single selector.");
                                }
                                parserInput.commentStore.length = 0;
                            }

                            if (selectors && (rules = this.block())) {
                                parserInput.forget();
                                var ruleset = new(tree.Ruleset)(selectors, rules, context.strictImports);
                                if (context.dumpLineNumbers) {
                                    ruleset.debugInfo = debugInfo;
                                }
                                return ruleset;
                            } else {
                                parserInput.restore();
                            }
                        },
                        rule: function(tryAnonymous) {
                            var name, value, startOfRule = parserInput.i,
                                c = parserInput.currentChar(),
                                important, merge, isVariable;

                            if (c === '.' || c === '#' || c === '&' || c === ':') { return; }

                            parserInput.save();

                            name = this.variable() || this.ruleProperty();
                            if (name) {
                                isVariable = typeof name === "string";

                                if (isVariable) {
                                    value = this.detachedRuleset();
                                }

                                parserInput.commentStore.length = 0;
                                if (!value) {
                                    // a name returned by this.ruleProperty() is always an array of the form:
                                    // [string-1, ..., string-n, ""] or [string-1, ..., string-n, "+"]
                                    // where each item is a tree.Keyword or tree.Variable
                                    merge = !isVariable && name.length > 1 && name.pop().value;

                                    // prefer to try to parse first if its a variable or we are compressing
                                    // but always fallback on the other one
                                    var tryValueFirst = !tryAnonymous && (context.compress || isVariable);

                                    if (tryValueFirst) {
                                        value = this.value();
                                    }
                                    if (!value) {
                                        value = this.anonymousValue();
                                        if (value) {
                                            parserInput.forget();
                                            // anonymous values absorb the end ';' which is required for them to work
                                            return new(tree.Rule)(name, value, false, merge, startOfRule, fileInfo);
                                        }
                                    }
                                    if (!tryValueFirst && !value) {
                                        value = this.value();
                                    }

                                    important = this.important();
                                }

                                if (value && this.end()) {
                                    parserInput.forget();
                                    return new(tree.Rule)(name, value, important, merge, startOfRule, fileInfo);
                                } else {
                                    parserInput.restore();
                                    if (value && !tryAnonymous) {
                                        return this.rule(true);
                                    }
                                }
                            } else {
                                parserInput.forget();
                            }
                        },
                        anonymousValue: function() {
                            var match = parserInput.$re(/^([^@+\/'"*`(;{}-]*);/);
                            if (match) {
                                return new(tree.Anonymous)(match[1]);
                            }
                        },

                        //
                        // An @import directive
                        //
                        //     @import "lib";
                        //
                        // Depending on our environment, importing is done differently:
                        // In the browser, it's an XHR request, in Node, it would be a
                        // file-system operation. The function used for importing is
                        // stored in `import`, which we pass to the Import constructor.
                        //
                        "import": function() {
                            var path, features, index = parserInput.i;

                            var dir = parserInput.$re(/^@import?\s+/);

                            if (dir) {
                                var options = (dir ? this.importOptions() : null) || {};

                                if ((path = this.entities.quoted() || this.entities.url())) {
                                    features = this.mediaFeatures();

                                    if (!parserInput.$char(';')) {
                                        parserInput.i = index;
                                        error("missing semi-colon or unrecognised media features on import");
                                    }
                                    features = features && new(tree.Value)(features);
                                    return new(tree.Import)(path, features, options, index, fileInfo);
                                } else {
                                    parserInput.i = index;
                                    error("malformed import statement");
                                }
                            }
                        },

                        importOptions: function() {
                            var o, options = {},
                                optionName, value;

                            // list of options, surrounded by parens
                            if (!parserInput.$char('(')) { return null; }
                            do {
                                o = this.importOption();
                                if (o) {
                                    optionName = o;
                                    value = true;
                                    switch (optionName) {
                                        case "css":
                                            optionName = "less";
                                            value = false;
                                            break;
                                        case "once":
                                            optionName = "multiple";
                                            value = false;
                                            break;
                                    }
                                    options[optionName] = value;
                                    if (!parserInput.$char(',')) { break; }
                                }
                            } while (o);
                            expectChar(')');
                            return options;
                        },

                        importOption: function() {
                            var opt = parserInput.$re(/^(less|css|multiple|once|inline|reference|optional)/);
                            if (opt) {
                                return opt[1];
                            }
                        },

                        mediaFeature: function() {
                            var entities = this.entities,
                                nodes = [],
                                e, p;
                            parserInput.save();
                            do {
                                e = entities.keyword() || entities.variable();
                                if (e) {
                                    nodes.push(e);
                                } else if (parserInput.$char('(')) {
                                    p = this.property();
                                    e = this.value();
                                    if (parserInput.$char(')')) {
                                        if (p && e) {
                                            nodes.push(new(tree.Paren)(new(tree.Rule)(p, e, null, null, parserInput.i, fileInfo, true)));
                                        } else if (e) {
                                            nodes.push(new(tree.Paren)(e));
                                        } else {
                                            parserInput.restore("badly formed media feature definition");
                                            return null;
                                        }
                                    } else {
                                        parserInput.restore("Missing closing ')'");
                                        return null;
                                    }
                                }
                            } while (e);

                            parserInput.forget();
                            if (nodes.length > 0) {
                                return new(tree.Expression)(nodes);
                            }
                        },

                        mediaFeatures: function() {
                            var entities = this.entities,
                                features = [],
                                e;
                            do {
                                e = this.mediaFeature();
                                if (e) {
                                    features.push(e);
                                    if (!parserInput.$char(',')) { break; }
                                } else {
                                    e = entities.variable();
                                    if (e) {
                                        features.push(e);
                                        if (!parserInput.$char(',')) { break; }
                                    }
                                }
                            } while (e);

                            return features.length > 0 ? features : null;
                        },

                        media: function() {
                            var features, rules, media, debugInfo;

                            if (context.dumpLineNumbers) {
                                debugInfo = getDebugInfo(parserInput.i);
                            }

                            parserInput.save();

                            if (parserInput.$str("@media")) {
                                features = this.mediaFeatures();

                                rules = this.block();

                                if (!rules) {
                                    parserInput.restore("media definitions require block statements after any features");
                                    return;
                                }

                                parserInput.forget();

                                media = new(tree.Media)(rules, features, parserInput.i, fileInfo);
                                if (context.dumpLineNumbers) {
                                    media.debugInfo = debugInfo;
                                }

                                return media;
                            }

                            parserInput.restore();
                        },

                        //
                        // A @plugin directive, used to import compiler extensions dynamically.
                        //
                        //     @plugin "lib";
                        //
                        // Depending on our environment, importing is done differently:
                        // In the browser, it's an XHR request, in Node, it would be a
                        // file-system operation. The function used for importing is
                        // stored in `import`, which we pass to the Import constructor.
                        //
                        plugin: function() {
                            var path,
                                index = parserInput.i,
                                dir = parserInput.$re(/^@plugin?\s+/);

                            if (dir) {
                                var options = { plugin: true };

                                if ((path = this.entities.quoted() || this.entities.url())) {

                                    if (!parserInput.$char(';')) {
                                        parserInput.i = index;
                                        error("missing semi-colon on plugin");
                                    }

                                    return new(tree.Import)(path, null, options, index, fileInfo);
                                } else {
                                    parserInput.i = index;
                                    error("malformed plugin statement");
                                }
                            }
                        },

                        //
                        // A CSS Directive
                        //
                        //     @charset "utf-8";
                        //
                        directive: function() {
                            var index = parserInput.i,
                                name, value, rules, nonVendorSpecificName,
                                hasIdentifier, hasExpression, hasUnknown, hasBlock = true,
                                isRooted = true;

                            if (parserInput.currentChar() !== '@') { return; }

                            value = this['import']() || this.plugin() || this.media();
                            if (value) {
                                return value;
                            }

                            parserInput.save();

                            name = parserInput.$re(/^@[a-z-]+/);

                            if (!name) { return; }

                            nonVendorSpecificName = name;
                            if (name.charAt(1) == '-' && name.indexOf('-', 2) > 0) {
                                nonVendorSpecificName = "@" + name.slice(name.indexOf('-', 2) + 1);
                            }

                            switch (nonVendorSpecificName) {
                                /*
                                case "@font-face":
                                case "@viewport":
                                case "@top-left":
                                case "@top-left-corner":
                                case "@top-center":
                                case "@top-right":
                                case "@top-right-corner":
                                case "@bottom-left":
                                case "@bottom-left-corner":
                                case "@bottom-center":
                                case "@bottom-right":
                                case "@bottom-right-corner":
                                case "@left-top":
                                case "@left-middle":
                                case "@left-bottom":
                                case "@right-top":
                                case "@right-middle":
                                case "@right-bottom":
                                    hasBlock = true;
                                    isRooted = true;
                                    break;
                                */
                                case "@counter-style":
                                    hasIdentifier = true;
                                    hasBlock = true;
                                    break;
                                case "@charset":
                                    hasIdentifier = true;
                                    hasBlock = false;
                                    break;
                                case "@namespace":
                                    hasExpression = true;
                                    hasBlock = false;
                                    break;
                                case "@keyframes":
                                    hasIdentifier = true;
                                    break;
                                case "@host":
                                case "@page":
                                    hasUnknown = true;
                                    break;
                                case "@document":
                                case "@supports":
                                    hasUnknown = true;
                                    isRooted = false;
                                    break;
                            }

                            parserInput.commentStore.length = 0;

                            if (hasIdentifier) {
                                value = this.entity();
                                if (!value) {
                                    error("expected " + name + " identifier");
                                }
                            } else if (hasExpression) {
                                value = this.expression();
                                if (!value) {
                                    error("expected " + name + " expression");
                                }
                            } else if (hasUnknown) {
                                value = (parserInput.$re(/^[^{;]+/) || '').trim();
                                if (value) {
                                    value = new(tree.Anonymous)(value);
                                }
                            }

                            if (hasBlock) {
                                rules = this.blockRuleset();
                            }

                            if (rules || (!hasBlock && value && parserInput.$char(';'))) {
                                parserInput.forget();
                                return new(tree.Directive)(name, value, rules, index, fileInfo,
                                    context.dumpLineNumbers ? getDebugInfo(index) : null,
                                    false,
                                    isRooted
                                );
                            }

                            parserInput.restore("directive options not recognised");
                        },

                        //
                        // A Value is a comma-delimited list of Expressions
                        //
                        //     font-family: Baskerville, Georgia, serif;
                        //
                        // In a Rule, a Value represents everything after the `:`,
                        // and before the `;`.
                        //
                        value: function() {
                            var e, expressions = [];

                            do {
                                e = this.expression();
                                if (e) {
                                    expressions.push(e);
                                    if (!parserInput.$char(',')) { break; }
                                }
                            } while (e);

                            if (expressions.length > 0) {
                                return new(tree.Value)(expressions);
                            }
                        },
                        important: function() {
                            if (parserInput.currentChar() === '!') {
                                return parserInput.$re(/^! *important/);
                            }
                        },
                        sub: function() {
                            var a, e;

                            parserInput.save();
                            if (parserInput.$char('(')) {
                                a = this.addition();
                                if (a && parserInput.$char(')')) {
                                    parserInput.forget();
                                    e = new(tree.Expression)([a]);
                                    e.parens = true;
                                    return e;
                                }
                                parserInput.restore("Expected ')'");
                                return;
                            }
                            parserInput.restore();
                        },
                        multiplication: function() {
                            var m, a, op, operation, isSpaced;
                            m = this.operand();
                            if (m) {
                                isSpaced = parserInput.isWhitespace(-1);
                                while (true) {
                                    if (parserInput.peek(/^\/[*\/]/)) {
                                        break;
                                    }

                                    parserInput.save();

                                    op = parserInput.$char('/') || parserInput.$char('*');

                                    if (!op) { parserInput.forget(); break; }

                                    a = this.operand();

                                    if (!a) { parserInput.restore(); break; }
                                    parserInput.forget();

                                    m.parensInOp = true;
                                    a.parensInOp = true;
                                    operation = new(tree.Operation)(op, [operation || m, a], isSpaced);
                                    isSpaced = parserInput.isWhitespace(-1);
                                }
                                return operation || m;
                            }
                        },
                        addition: function() {
                            var m, a, op, operation, isSpaced;
                            m = this.multiplication();
                            if (m) {
                                isSpaced = parserInput.isWhitespace(-1);
                                while (true) {
                                    op = parserInput.$re(/^[-+]\s+/) || (!isSpaced && (parserInput.$char('+') || parserInput.$char('-')));
                                    if (!op) {
                                        break;
                                    }
                                    a = this.multiplication();
                                    if (!a) {
                                        break;
                                    }

                                    m.parensInOp = true;
                                    a.parensInOp = true;
                                    operation = new(tree.Operation)(op, [operation || m, a], isSpaced);
                                    isSpaced = parserInput.isWhitespace(-1);
                                }
                                return operation || m;
                            }
                        },
                        conditions: function() {
                            var a, b, index = parserInput.i,
                                condition;

                            a = this.condition();
                            if (a) {
                                while (true) {
                                    if (!parserInput.peek(/^,\s*(not\s*)?\(/) || !parserInput.$char(',')) {
                                        break;
                                    }
                                    b = this.condition();
                                    if (!b) {
                                        break;
                                    }
                                    condition = new(tree.Condition)('or', condition || a, b, index);
                                }
                                return condition || a;
                            }
                        },
                        condition: function() {
                            var entities = this.entities,
                                index = parserInput.i,
                                negate = false,
                                a, b, c, op;

                            if (parserInput.$str("not")) { negate = true; }
                            expectChar('(');
                            a = this.addition() || entities.keyword() || entities.quoted();
                            if (a) {
                                if (parserInput.$char('>')) {
                                    if (parserInput.$char('=')) {
                                        op = ">=";
                                    } else {
                                        op = '>';
                                    }
                                } else
                                if (parserInput.$char('<')) {
                                    if (parserInput.$char('=')) {
                                        op = "<=";
                                    } else {
                                        op = '<';
                                    }
                                } else
                                if (parserInput.$char('=')) {
                                    if (parserInput.$char('>')) {
                                        op = "=>";
                                    } else if (parserInput.$char('<')) {
                                        op = '=<';
                                    } else {
                                        op = '=';
                                    }
                                }
                                if (op) {
                                    b = this.addition() || entities.keyword() || entities.quoted();
                                    if (b) {
                                        c = new(tree.Condition)(op, a, b, index, negate);
                                    } else {
                                        error('expected expression');
                                    }
                                } else {
                                    c = new(tree.Condition)('=', a, new(tree.Keyword)('true'), index, negate);
                                }
                                expectChar(')');
                                return parserInput.$str("and") ? new(tree.Condition)('and', c, this.condition()) : c;
                            }
                        },

                        //
                        // An operand is anything that can be part of an operation,
                        // such as a Color, or a Variable
                        //
                        operand: function() {
                            var entities = this.entities,
                                negate;

                            if (parserInput.peek(/^-[@\(]/)) {
                                negate = parserInput.$char('-');
                            }

                            var o = this.sub() || entities.dimension() ||
                                entities.color() || entities.variable() ||
                                entities.call();

                            if (negate) {
                                o.parensInOp = true;
                                o = new(tree.Negative)(o);
                            }

                            return o;
                        },

                        //
                        // Expressions either represent mathematical operations,
                        // or white-space delimited Entities.
                        //
                        //     1px solid black
                        //     @var * 2
                        //
                        expression: function() {
                            var entities = [],
                                e, delim;

                            do {
                                e = this.comment();
                                if (e) {
                                    entities.push(e);
                                    continue;
                                }
                                e = this.addition() || this.entity();
                                if (e) {
                                    entities.push(e);
                                    // operations do not allow keyword "/" dimension (e.g. small/20px) so we support that here
                                    if (!parserInput.peek(/^\/[\/*]/)) {
                                        delim = parserInput.$char('/');
                                        if (delim) {
                                            entities.push(new(tree.Anonymous)(delim));
                                        }
                                    }
                                }
                            } while (e);
                            if (entities.length > 0) {
                                return new(tree.Expression)(entities);
                            }
                        },
                        property: function() {
                            var name = parserInput.$re(/^(\*?-?[_a-zA-Z0-9-]+)\s*:/);
                            if (name) {
                                return name[1];
                            }
                        },
                        ruleProperty: function() {
                            var name = [],
                                index = [],
                                s, k;

                            parserInput.save();

                            var simpleProperty = parserInput.$re(/^([_a-zA-Z0-9-]+)\s*:/);
                            if (simpleProperty) {
                                name = [new(tree.Keyword)(simpleProperty[1])];
                                parserInput.forget();
                                return name;
                            }

                            function match(re) {
                                var i = parserInput.i,
                                    chunk = parserInput.$re(re);
                                if (chunk) {
                                    index.push(i);
                                    return name.push(chunk[1]);
                                }
                            }

                            match(/^(\*?)/);
                            while (true) {
                                if (!match(/^((?:[\w-]+)|(?:@\{[\w-]+\}))/)) {
                                    break;
                                }
                            }

                            if ((name.length > 1) && match(/^((?:\+_|\+)?)\s*:/)) {
                                parserInput.forget();

                                // at last, we have the complete match now. move forward,
                                // convert name particles to tree objects and return:
                                if (name[0] === '') {
                                    name.shift();
                                    index.shift();
                                }
                                for (k = 0; k < name.length; k++) {
                                    s = name[k];
                                    name[k] = (s.charAt(0) !== '@') ?
                                        new(tree.Keyword)(s) :
                                        new(tree.Variable)('@' + s.slice(2, -1),
                                            index[k], fileInfo);
                                }
                                return name;
                            }
                            parserInput.restore();
                        }
                    }
                };
            };
            Parser.serializeVars = function(vars) {
                var s = '';

                for (var name in vars) {
                    if (Object.hasOwnProperty.call(vars, name)) {
                        var value = vars[name];
                        s += ((name[0] === '@') ? '' : '@') + name + ': ' + value +
                            ((String(value).slice(-1) === ';') ? '' : ';');
                    }
                }

                return s;
            };

            module.exports = Parser;

        }, { "../less-error": 30, "../tree": 60, "../utils": 81, "../visitors": 85, "./parser-input": 35 }],
        37: [function(require, module, exports) {
            /**
             * Plugin Manager
             */
            var PluginManager = function(less) {
                this.less = less;
                this.visitors = [];
                this.preProcessors = [];
                this.postProcessors = [];
                this.installedPlugins = [];
                this.fileManagers = [];
            };
            /**
             * Adds all the plugins in the array
             * @param {Array} plugins
             */
            PluginManager.prototype.addPlugins = function(plugins) {
                if (plugins) {
                    for (var i = 0; i < plugins.length; i++) {
                        this.addPlugin(plugins[i]);
                    }
                }
            };
            /**
             *
             * @param plugin
             */
            PluginManager.prototype.addPlugin = function(plugin) {
                this.installedPlugins.push(plugin);
                plugin.install(this.less, this);
            };
            /**
             * Adds a visitor. The visitor object has options on itself to determine
             * when it should run.
             * @param visitor
             */
            PluginManager.prototype.addVisitor = function(visitor) {
                this.visitors.push(visitor);
            };
            /**
             * Adds a pre processor object
             * @param {object} preProcessor
             * @param {number} priority - guidelines 1 = before import, 1000 = import, 2000 = after import
             */
            PluginManager.prototype.addPreProcessor = function(preProcessor, priority) {
                var indexToInsertAt;
                for (indexToInsertAt = 0; indexToInsertAt < this.preProcessors.length; indexToInsertAt++) {
                    if (this.preProcessors[indexToInsertAt].priority >= priority) {
                        break;
                    }
                }
                this.preProcessors.splice(indexToInsertAt, 0, { preProcessor: preProcessor, priority: priority });
            };
            /**
             * Adds a post processor object
             * @param {object} postProcessor
             * @param {number} priority - guidelines 1 = before compression, 1000 = compression, 2000 = after compression
             */
            PluginManager.prototype.addPostProcessor = function(postProcessor, priority) {
                var indexToInsertAt;
                for (indexToInsertAt = 0; indexToInsertAt < this.postProcessors.length; indexToInsertAt++) {
                    if (this.postProcessors[indexToInsertAt].priority >= priority) {
                        break;
                    }
                }
                this.postProcessors.splice(indexToInsertAt, 0, { postProcessor: postProcessor, priority: priority });
            };
            /**
             *
             * @param manager
             */
            PluginManager.prototype.addFileManager = function(manager) {
                this.fileManagers.push(manager);
            };
            /**
             *
             * @returns {Array}
             * @private
             */
            PluginManager.prototype.getPreProcessors = function() {
                var preProcessors = [];
                for (var i = 0; i < this.preProcessors.length; i++) {
                    preProcessors.push(this.preProcessors[i].preProcessor);
                }
                return preProcessors;
            };
            /**
             *
             * @returns {Array}
             * @private
             */
            PluginManager.prototype.getPostProcessors = function() {
                var postProcessors = [];
                for (var i = 0; i < this.postProcessors.length; i++) {
                    postProcessors.push(this.postProcessors[i].postProcessor);
                }
                return postProcessors;
            };
            /**
             *
             * @returns {Array}
             * @private
             */
            PluginManager.prototype.getVisitors = function() {
                return this.visitors;
            };
            /**
             *
             * @returns {Array}
             * @private
             */
            PluginManager.prototype.getFileManagers = function() {
                return this.fileManagers;
            };
            module.exports = PluginManager;

        }, {}],
        38: [function(require, module, exports) {
            var LessError = require('../less-error'),
                tree = require("../tree");

            var FunctionImporter = module.exports = function FunctionImporter(context, fileInfo) {
                this.fileInfo = fileInfo;
            };

            FunctionImporter.prototype.eval = function(contents, callback) {
                var loaded = {},
                    loader,
                    registry;

                registry = {
                    add: function(name, func) {
                        loaded[name] = func;
                    },
                    addMultiple: function(functions) {
                        Object.keys(functions).forEach(function(name) {
                            loaded[name] = functions[name];
                        });
                    }
                };

                try {
                    loader = new Function("functions", "tree", "fileInfo", contents);
                    loader(registry, tree, this.fileInfo);
                } catch (e) {
                    callback(new LessError({
                        message: "Plugin evaluation error: '" + e.name + ': ' + e.message.replace(/["]/g, "'") + "'",
                        filename: this.fileInfo.filename
                    }), null);
                }

                callback(null, { functions: loaded });
            };

        }, { "../less-error": 30, "../tree": 60 }],
        39: [function(require, module, exports) {
            var PromiseConstructor;

            module.exports = function(environment, ParseTree, ImportManager) {
                var render = function(input, options, callback) {
                    if (typeof options === 'function') {
                        callback = options;
                        options = {};
                    }

                    if (!callback) {
                        if (!PromiseConstructor) {
                            PromiseConstructor = typeof Promise === 'undefined' ? require('promise') : Promise;
                        }
                        var self = this;
                        return new PromiseConstructor(function(resolve, reject) {
                            render.call(self, input, options, function(err, output) {
                                if (err) {
                                    reject(err);
                                } else {
                                    resolve(output);
                                }
                            });
                        });
                    } else {
                        this.parse(input, options, function(err, root, imports, options) {
                            if (err) { return callback(err); }

                            var result;
                            try {
                                var parseTree = new ParseTree(root, imports);
                                result = parseTree.toCSS(options);
                            } catch (err) { return callback(err); }

                            callback(null, result);
                        });
                    }
                };

                return render;
            };

        }, { "promise": undefined }],
        40: [function(require, module, exports) {
            module.exports = function(SourceMapOutput, environment) {

                var SourceMapBuilder = function(options) {
                    this.options = options;
                };

                SourceMapBuilder.prototype.toCSS = function(rootNode, options, imports) {
                    var sourceMapOutput = new SourceMapOutput({
                        contentsIgnoredCharsMap: imports.contentsIgnoredChars,
                        rootNode: rootNode,
                        contentsMap: imports.contents,
                        sourceMapFilename: this.options.sourceMapFilename,
                        sourceMapURL: this.options.sourceMapURL,
                        outputFilename: this.options.sourceMapOutputFilename,
                        sourceMapBasepath: this.options.sourceMapBasepath,
                        sourceMapRootpath: this.options.sourceMapRootpath,
                        outputSourceFiles: this.options.outputSourceFiles,
                        sourceMapGenerator: this.options.sourceMapGenerator,
                        sourceMapFileInline: this.options.sourceMapFileInline
                    });

                    var css = sourceMapOutput.toCSS(options);
                    this.sourceMap = sourceMapOutput.sourceMap;
                    this.sourceMapURL = sourceMapOutput.sourceMapURL;
                    if (this.options.sourceMapInputFilename) {
                        this.sourceMapInputFilename = sourceMapOutput.normalizeFilename(this.options.sourceMapInputFilename);
                    }
                    return css + this.getCSSAppendage();
                };

                SourceMapBuilder.prototype.getCSSAppendage = function() {

                    var sourceMapURL = this.sourceMapURL;
                    if (this.options.sourceMapFileInline) {
                        if (this.sourceMap === undefined) {
                            return "";
                        }
                        sourceMapURL = "data:application/json;base64," + environment.encodeBase64(this.sourceMap);
                    }

                    if (sourceMapURL) {
                        return "/*# sourceMappingURL=" + sourceMapURL + " */";
                    }
                    return "";
                };

                SourceMapBuilder.prototype.getExternalSourceMap = function() {
                    return this.sourceMap;
                };
                SourceMapBuilder.prototype.setExternalSourceMap = function(sourceMap) {
                    this.sourceMap = sourceMap;
                };

                SourceMapBuilder.prototype.isInline = function() {
                    return this.options.sourceMapFileInline;
                };
                SourceMapBuilder.prototype.getSourceMapURL = function() {
                    return this.sourceMapURL;
                };
                SourceMapBuilder.prototype.getOutputFilename = function() {
                    return this.options.sourceMapOutputFilename;
                };
                SourceMapBuilder.prototype.getInputFilename = function() {
                    return this.sourceMapInputFilename;
                };

                return SourceMapBuilder;
            };

        }, {}],
        41: [function(require, module, exports) {
            module.exports = function(environment) {

                var SourceMapOutput = function(options) {
                    this._css = [];
                    this._rootNode = options.rootNode;
                    this._contentsMap = options.contentsMap;
                    this._contentsIgnoredCharsMap = options.contentsIgnoredCharsMap;
                    if (options.sourceMapFilename) {
                        this._sourceMapFilename = options.sourceMapFilename.replace(/\\/g, '/');
                    }
                    this._outputFilename = options.outputFilename;
                    this.sourceMapURL = options.sourceMapURL;
                    if (options.sourceMapBasepath) {
                        this._sourceMapBasepath = options.sourceMapBasepath.replace(/\\/g, '/');
                    }
                    if (options.sourceMapRootpath) {
                        this._sourceMapRootpath = options.sourceMapRootpath.replace(/\\/g, '/');
                        if (this._sourceMapRootpath.charAt(this._sourceMapRootpath.length - 1) !== '/') {
                            this._sourceMapRootpath += '/';
                        }
                    } else {
                        this._sourceMapRootpath = "";
                    }
                    this._outputSourceFiles = options.outputSourceFiles;
                    this._sourceMapGeneratorConstructor = environment.getSourceMapGenerator();

                    this._lineNumber = 0;
                    this._column = 0;
                };

                SourceMapOutput.prototype.normalizeFilename = function(filename) {
                    filename = filename.replace(/\\/g, '/');

                    if (this._sourceMapBasepath && filename.indexOf(this._sourceMapBasepath) === 0) {
                        filename = filename.substring(this._sourceMapBasepath.length);
                        if (filename.charAt(0) === '\\' || filename.charAt(0) === '/') {
                            filename = filename.substring(1);
                        }
                    }
                    return (this._sourceMapRootpath || "") + filename;
                };

                SourceMapOutput.prototype.add = function(chunk, fileInfo, index, mapLines) {

                    //ignore adding empty strings
                    if (!chunk) {
                        return;
                    }

                    var lines,
                        sourceLines,
                        columns,
                        sourceColumns,
                        i;

                    if (fileInfo) {
                        var inputSource = this._contentsMap[fileInfo.filename];

                        // remove vars/banner added to the top of the file
                        if (this._contentsIgnoredCharsMap[fileInfo.filename]) {
                            // adjust the index
                            index -= this._contentsIgnoredCharsMap[fileInfo.filename];
                            if (index < 0) { index = 0; }
                            // adjust the source
                            inputSource = inputSource.slice(this._contentsIgnoredCharsMap[fileInfo.filename]);
                        }
                        inputSource = inputSource.substring(0, index);
                        sourceLines = inputSource.split("\n");
                        sourceColumns = sourceLines[sourceLines.length - 1];
                    }

                    lines = chunk.split("\n");
                    columns = lines[lines.length - 1];

                    if (fileInfo) {
                        if (!mapLines) {
                            this._sourceMapGenerator.addMapping({
                                generated: { line: this._lineNumber + 1, column: this._column },
                                original: { line: sourceLines.length, column: sourceColumns.length },
                                source: this.normalizeFilename(fileInfo.filename)
                            });
                        } else {
                            for (i = 0; i < lines.length; i++) {
                                this._sourceMapGenerator.addMapping({
                                    generated: { line: this._lineNumber + i + 1, column: i === 0 ? this._column : 0 },
                                    original: { line: sourceLines.length + i, column: i === 0 ? sourceColumns.length : 0 },
                                    source: this.normalizeFilename(fileInfo.filename)
                                });
                            }
                        }
                    }

                    if (lines.length === 1) {
                        this._column += columns.length;
                    } else {
                        this._lineNumber += lines.length - 1;
                        this._column = columns.length;
                    }

                    this._css.push(chunk);
                };

                SourceMapOutput.prototype.isEmpty = function() {
                    return this._css.length === 0;
                };

                SourceMapOutput.prototype.toCSS = function(context) {
                    this._sourceMapGenerator = new this._sourceMapGeneratorConstructor({ file: this._outputFilename, sourceRoot: null });

                    if (this._outputSourceFiles) {
                        for (var filename in this._contentsMap) {
                            if (this._contentsMap.hasOwnProperty(filename)) {
                                var source = this._contentsMap[filename];
                                if (this._contentsIgnoredCharsMap[filename]) {
                                    source = source.slice(this._contentsIgnoredCharsMap[filename]);
                                }
                                this._sourceMapGenerator.setSourceContent(this.normalizeFilename(filename), source);
                            }
                        }
                    }

                    this._rootNode.genCSS(context, this);

                    if (this._css.length > 0) {
                        var sourceMapURL,
                            sourceMapContent = JSON.stringify(this._sourceMapGenerator.toJSON());

                        if (this.sourceMapURL) {
                            sourceMapURL = this.sourceMapURL;
                        } else if (this._sourceMapFilename) {
                            sourceMapURL = this._sourceMapFilename;
                        }
                        this.sourceMapURL = sourceMapURL;

                        this.sourceMap = sourceMapContent;
                    }

                    return this._css.join('');
                };

                return SourceMapOutput;
            };

        }, {}],
        42: [function(require, module, exports) {
            var contexts = require("./contexts"),
                visitor = require("./visitors"),
                tree = require("./tree");

            module.exports = function(root, options) {
                options = options || {};
                var evaldRoot,
                    variables = options.variables,
                    evalEnv = new contexts.Eval(options);

                //
                // Allows setting variables with a hash, so:
                //
                //   `{ color: new tree.Color('#f01') }` will become:
                //
                //   new tree.Rule('@color',
                //     new tree.Value([
                //       new tree.Expression([
                //         new tree.Color('#f01')
                //       ])
                //     ])
                //   )
                //
                if (typeof variables === 'object' && !Array.isArray(variables)) {
                    variables = Object.keys(variables).map(function(k) {
                        var value = variables[k];

                        if (!(value instanceof tree.Value)) {
                            if (!(value instanceof tree.Expression)) {
                                value = new tree.Expression([value]);
                            }
                            value = new tree.Value([value]);
                        }
                        return new tree.Rule('@' + k, value, false, null, 0);
                    });
                    evalEnv.frames = [new tree.Ruleset(null, variables)];
                }

                var preEvalVisitors = [],
                    visitors = [
                        new visitor.JoinSelectorVisitor(),
                        new visitor.ExtendVisitor(),
                        new visitor.ToCSSVisitor({ compress: Boolean(options.compress) })
                    ],
                    i;

                if (options.pluginManager) {
                    var pluginVisitors = options.pluginManager.getVisitors();
                    for (i = 0; i < pluginVisitors.length; i++) {
                        var pluginVisitor = pluginVisitors[i];
                        if (pluginVisitor.isPreEvalVisitor) {
                            preEvalVisitors.push(pluginVisitor);
                        } else {
                            if (pluginVisitor.isPreVisitor) {
                                visitors.splice(0, 0, pluginVisitor);
                            } else {
                                visitors.push(pluginVisitor);
                            }
                        }
                    }
                }

                for (i = 0; i < preEvalVisitors.length; i++) {
                    preEvalVisitors[i].run(root);
                }

                evaldRoot = root.eval(evalEnv);

                for (i = 0; i < visitors.length; i++) {
                    visitors[i].run(evaldRoot);
                }

                return evaldRoot;
            };

        }, { "./contexts": 10, "./tree": 60, "./visitors": 85 }],
        43: [function(require, module, exports) {
            var Node = require("./node");

            var Alpha = function(val) {
                this.value = val;
            };
            Alpha.prototype = new Node();
            Alpha.prototype.type = "Alpha";

            Alpha.prototype.accept = function(visitor) {
                this.value = visitor.visit(this.value);
            };
            Alpha.prototype.eval = function(context) {
                if (this.value.eval) { return new Alpha(this.value.eval(context)); }
                return this;
            };
            Alpha.prototype.genCSS = function(context, output) {
                output.add("alpha(opacity=");

                if (this.value.genCSS) {
                    this.value.genCSS(context, output);
                } else {
                    output.add(this.value);
                }

                output.add(")");
            };

            module.exports = Alpha;

        }, { "./node": 68 }],
        44: [function(require, module, exports) {
            var Node = require("./node");

            var Anonymous = function(value, index, currentFileInfo, mapLines, rulesetLike) {
                this.value = value;
                this.index = index;
                this.mapLines = mapLines;
                this.currentFileInfo = currentFileInfo;
                this.rulesetLike = (typeof rulesetLike === 'undefined') ? false : rulesetLike;
            };
            Anonymous.prototype = new Node();
            Anonymous.prototype.type = "Anonymous";
            Anonymous.prototype.eval = function() {
                return new Anonymous(this.value, this.index, this.currentFileInfo, this.mapLines, this.rulesetLike);
            };
            Anonymous.prototype.compare = function(other) {
                return other.toCSS && this.toCSS() === other.toCSS() ? 0 : undefined;
            };
            Anonymous.prototype.isRulesetLike = function() {
                return this.rulesetLike;
            };
            Anonymous.prototype.genCSS = function(context, output) {
                output.add(this.value, this.currentFileInfo, this.index, this.mapLines);
            };
            module.exports = Anonymous;

        }, { "./node": 68 }],
        45: [function(require, module, exports) {
            var Node = require("./node");

            var Assignment = function(key, val) {
                this.key = key;
                this.value = val;
            };

            Assignment.prototype = new Node();
            Assignment.prototype.type = "Assignment";
            Assignment.prototype.accept = function(visitor) {
                this.value = visitor.visit(this.value);
            };
            Assignment.prototype.eval = function(context) {
                if (this.value.eval) {
                    return new Assignment(this.key, this.value.eval(context));
                }
                return this;
            };
            Assignment.prototype.genCSS = function(context, output) {
                output.add(this.key + '=');
                if (this.value.genCSS) {
                    this.value.genCSS(context, output);
                } else {
                    output.add(this.value);
                }
            };
            module.exports = Assignment;

        }, { "./node": 68 }],
        46: [function(require, module, exports) {
            var Node = require("./node");

            var Attribute = function(key, op, value) {
                this.key = key;
                this.op = op;
                this.value = value;
            };
            Attribute.prototype = new Node();
            Attribute.prototype.type = "Attribute";
            Attribute.prototype.eval = function(context) {
                return new Attribute(this.key.eval ? this.key.eval(context) : this.key,
                    this.op, (this.value && this.value.eval) ? this.value.eval(context) : this.value);
            };
            Attribute.prototype.genCSS = function(context, output) {
                output.add(this.toCSS(context));
            };
            Attribute.prototype.toCSS = function(context) {
                var value = this.key.toCSS ? this.key.toCSS(context) : this.key;

                if (this.op) {
                    value += this.op;
                    value += (this.value.toCSS ? this.value.toCSS(context) : this.value);
                }

                return '[' + value + ']';
            };
            module.exports = Attribute;

        }, { "./node": 68 }],
        47: [function(require, module, exports) {
            var Node = require("./node"),
                FunctionCaller = require("../functions/function-caller");
            //
            // A function call node.
            //
            var Call = function(name, args, index, currentFileInfo) {
                this.name = name;
                this.args = args;
                this.index = index;
                this.currentFileInfo = currentFileInfo;
            };
            Call.prototype = new Node();
            Call.prototype.type = "Call";
            Call.prototype.accept = function(visitor) {
                if (this.args) {
                    this.args = visitor.visitArray(this.args);
                }
            };
            //
            // When evaluating a function call,
            // we either find the function in the functionRegistry,
            // in which case we call it, passing the  evaluated arguments,
            // if this returns null or we cannot find the function, we
            // simply print it out as it appeared originally [2].
            //
            // The reason why we evaluate the arguments, is in the case where
            // we try to pass a variable to a function, like: `saturate(@color)`.
            // The function should receive the value, not the variable.
            //
            Call.prototype.eval = function(context) {
                var args = this.args.map(function(a) { return a.eval(context); }),
                    result, funcCaller = new FunctionCaller(this.name, context, this.index, this.currentFileInfo);

                if (funcCaller.isValid()) { // 1.
                    try {
                        result = funcCaller.call(args);
                        if (result != null) {
                            return result;
                        }
                    } catch (e) {
                        throw {
                            type: e.type || "Runtime",
                            message: "error evaluating function `" + this.name + "`" +
                                (e.message ? ': ' + e.message : ''),
                            index: this.index,
                            filename: this.currentFileInfo.filename
                        };
                    }
                }

                return new Call(this.name, args, this.index, this.currentFileInfo);
            };
            Call.prototype.genCSS = function(context, output) {
                output.add(this.name + "(", this.currentFileInfo, this.index);

                for (var i = 0; i < this.args.length; i++) {
                    this.args[i].genCSS(context, output);
                    if (i + 1 < this.args.length) {
                        output.add(", ");
                    }
                }

                output.add(")");
            };
            module.exports = Call;

        }, { "../functions/function-caller": 20, "./node": 68 }],
        48: [function(require, module, exports) {
            var Node = require("./node"),
                colors = require("../data/colors");

            //
            // RGB Colors - #ff0014, #eee
            //
            var Color = function(rgb, a) {
                //
                // The end goal here, is to parse the arguments
                // into an integer triplet, such as `128, 255, 0`
                //
                // This facilitates operations and conversions.
                //
                if (Array.isArray(rgb)) {
                    this.rgb = rgb;
                } else if (rgb.length == 6) {
                    this.rgb = rgb.match(/.{2}/g).map(function(c) {
                        return parseInt(c, 16);
                    });
                } else {
                    this.rgb = rgb.split('').map(function(c) {
                        return parseInt(c + c, 16);
                    });
                }
                this.alpha = typeof a === 'number' ? a : 1;
            };

            Color.prototype = new Node();
            Color.prototype.type = "Color";

            function clamp(v, max) {
                return Math.min(Math.max(v, 0), max);
            }

            function toHex(v) {
                return '#' + v.map(function(c) {
                    c = clamp(Math.round(c), 255);
                    return (c < 16 ? '0' : '') + c.toString(16);
                }).join('');
            }

            Color.prototype.luma = function() {
                var r = this.rgb[0] / 255,
                    g = this.rgb[1] / 255,
                    b = this.rgb[2] / 255;

                r = (r <= 0.03928) ? r / 12.92 : Math.pow(((r + 0.055) / 1.055), 2.4);
                g = (g <= 0.03928) ? g / 12.92 : Math.pow(((g + 0.055) / 1.055), 2.4);
                b = (b <= 0.03928) ? b / 12.92 : Math.pow(((b + 0.055) / 1.055), 2.4);

                return 0.2126 * r + 0.7152 * g + 0.0722 * b;
            };
            Color.prototype.genCSS = function(context, output) {
                output.add(this.toCSS(context));
            };
            Color.prototype.toCSS = function(context, doNotCompress) {
                var compress = context && context.compress && !doNotCompress,
                    color, alpha;

                // `value` is set if this color was originally
                // converted from a named color string so we need
                // to respect this and try to output named color too.
                if (this.value) {
                    return this.value;
                }

                // If we have some transparency, the only way to represent it
                // is via `rgba`. Otherwise, we use the hex representation,
                // which has better compatibility with older browsers.
                // Values are capped between `0` and `255`, rounded and zero-padded.
                alpha = this.fround(context, this.alpha);
                if (alpha < 1) {
                    return "rgba(" + this.rgb.map(function(c) {
                            return clamp(Math.round(c), 255);
                        }).concat(clamp(alpha, 1))
                        .join(',' + (compress ? '' : ' ')) + ")";
                }

                color = this.toRGB();

                if (compress) {
                    var splitcolor = color.split('');

                    // Convert color to short format
                    if (splitcolor[1] === splitcolor[2] && splitcolor[3] === splitcolor[4] && splitcolor[5] === splitcolor[6]) {
                        color = '#' + splitcolor[1] + splitcolor[3] + splitcolor[5];
                    }
                }

                return color;
            };

            //
            // Operations have to be done per-channel, if not,
            // channels will spill onto each other. Once we have
            // our result, in the form of an integer triplet,
            // we create a new Color node to hold the result.
            //
            Color.prototype.operate = function(context, op, other) {
                var rgb = [];
                var alpha = this.alpha * (1 - other.alpha) + other.alpha;
                for (var c = 0; c < 3; c++) {
                    rgb[c] = this._operate(context, op, this.rgb[c], other.rgb[c]);
                }
                return new Color(rgb, alpha);
            };
            Color.prototype.toRGB = function() {
                return toHex(this.rgb);
            };
            Color.prototype.toHSL = function() {
                var r = this.rgb[0] / 255,
                    g = this.rgb[1] / 255,
                    b = this.rgb[2] / 255,
                    a = this.alpha;

                var max = Math.max(r, g, b),
                    min = Math.min(r, g, b);
                var h, s, l = (max + min) / 2,
                    d = max - min;

                if (max === min) {
                    h = s = 0;
                } else {
                    s = l > 0.5 ? d / (2 - max - min) : d / (max + min);

                    switch (max) {
                        case r:
                            h = (g - b) / d + (g < b ? 6 : 0);
                            break;
                        case g:
                            h = (b - r) / d + 2;
                            break;
                        case b:
                            h = (r - g) / d + 4;
                            break;
                    }
                    h /= 6;
                }
                return { h: h * 360, s: s, l: l, a: a };
            };
            //Adapted from http://mjijackson.com/2008/02/rgb-to-hsl-and-rgb-to-hsv-color-model-conversion-algorithms-in-javascript
            Color.prototype.toHSV = function() {
                var r = this.rgb[0] / 255,
                    g = this.rgb[1] / 255,
                    b = this.rgb[2] / 255,
                    a = this.alpha;

                var max = Math.max(r, g, b),
                    min = Math.min(r, g, b);
                var h, s, v = max;

                var d = max - min;
                if (max === 0) {
                    s = 0;
                } else {
                    s = d / max;
                }

                if (max === min) {
                    h = 0;
                } else {
                    switch (max) {
                        case r:
                            h = (g - b) / d + (g < b ? 6 : 0);
                            break;
                        case g:
                            h = (b - r) / d + 2;
                            break;
                        case b:
                            h = (r - g) / d + 4;
                            break;
                    }
                    h /= 6;
                }
                return { h: h * 360, s: s, v: v, a: a };
            };
            Color.prototype.toARGB = function() {
                return toHex([this.alpha * 255].concat(this.rgb));
            };
            Color.prototype.compare = function(x) {
                return (x.rgb &&
                    x.rgb[0] === this.rgb[0] &&
                    x.rgb[1] === this.rgb[1] &&
                    x.rgb[2] === this.rgb[2] &&
                    x.alpha === this.alpha) ? 0 : undefined;
            };

            Color.fromKeyword = function(keyword) {
                var c, key = keyword.toLowerCase();
                if (colors.hasOwnProperty(key)) {
                    c = new Color(colors[key].slice(1));
                } else if (key === "transparent") {
                    c = new Color([0, 0, 0], 0);
                }

                if (c) {
                    c.value = keyword;
                    return c;
                }
            };
            module.exports = Color;

        }, { "../data/colors": 11, "./node": 68 }],
        49: [function(require, module, exports) {
            var Node = require("./node");

            var Combinator = function(value) {
                if (value === ' ') {
                    this.value = ' ';
                    this.emptyOrWhitespace = true;
                } else {
                    this.value = value ? value.trim() : "";
                    this.emptyOrWhitespace = this.value === "";
                }
            };
            Combinator.prototype = new Node();
            Combinator.prototype.type = "Combinator";
            var _noSpaceCombinators = {
                '': true,
                ' ': true,
                '|': true
            };
            Combinator.prototype.genCSS = function(context, output) {
                var spaceOrEmpty = (context.compress || _noSpaceCombinators[this.value]) ? '' : ' ';
                output.add(spaceOrEmpty + this.value + spaceOrEmpty);
            };
            module.exports = Combinator;

        }, { "./node": 68 }],
        50: [function(require, module, exports) {
            var Node = require("./node"),
                getDebugInfo = require("./debug-info");

            var Comment = function(value, isLineComment, index, currentFileInfo) {
                this.value = value;
                this.isLineComment = isLineComment;
                this.currentFileInfo = currentFileInfo;
            };
            Comment.prototype = new Node();
            Comment.prototype.type = "Comment";
            Comment.prototype.genCSS = function(context, output) {
                if (this.debugInfo) {
                    output.add(getDebugInfo(context, this), this.currentFileInfo, this.index);
                }
                output.add(this.value);
            };
            Comment.prototype.isSilent = function(context) {
                var isReference = (this.currentFileInfo && this.currentFileInfo.reference && !this.isReferenced),
                    isCompressed = context.compress && this.value[2] !== "!";
                return this.isLineComment || isReference || isCompressed;
            };
            Comment.prototype.markReferenced = function() {
                this.isReferenced = true;
            };
            module.exports = Comment;

        }, { "./debug-info": 52, "./node": 68 }],
        51: [function(require, module, exports) {
            var Node = require("./node");

            var Condition = function(op, l, r, i, negate) {
                this.op = op.trim();
                this.lvalue = l;
                this.rvalue = r;
                this.index = i;
                this.negate = negate;
            };
            Condition.prototype = new Node();
            Condition.prototype.type = "Condition";
            Condition.prototype.accept = function(visitor) {
                this.lvalue = visitor.visit(this.lvalue);
                this.rvalue = visitor.visit(this.rvalue);
            };
            Condition.prototype.eval = function(context) {
                var result = (function(op, a, b) {
                    switch (op) {
                        case 'and':
                            return a && b;
                        case 'or':
                            return a || b;
                        default:
                            switch (Node.compare(a, b)) {
                                case -1:
                                    return op === '<' || op === '=<' || op === '<=';
                                case 0:
                                    return op === '=' || op === '>=' || op === '=<' || op === '<=';
                                case 1:
                                    return op === '>' || op === '>=';
                                default:
                                    return false;
                            }
                    }
                })(this.op, this.lvalue.eval(context), this.rvalue.eval(context));

                return this.negate ? !result : result;
            };
            module.exports = Condition;

        }, { "./node": 68 }],
        52: [function(require, module, exports) {
            var debugInfo = function(context, ctx, lineSeparator) {
                var result = "";
                if (context.dumpLineNumbers && !context.compress) {
                    switch (context.dumpLineNumbers) {
                        case 'comments':
                            result = debugInfo.asComment(ctx);
                            break;
                        case 'mediaquery':
                            result = debugInfo.asMediaQuery(ctx);
                            break;
                        case 'all':
                            result = debugInfo.asComment(ctx) + (lineSeparator || "") + debugInfo.asMediaQuery(ctx);
                            break;
                    }
                }
                return result;
            };

            debugInfo.asComment = function(ctx) {
                return '/* line ' + ctx.debugInfo.lineNumber + ', ' + ctx.debugInfo.fileName + ' */\n';
            };

            debugInfo.asMediaQuery = function(ctx) {
                var filenameWithProtocol = ctx.debugInfo.fileName;
                if (!/^[a-z]+:\/\//i.test(filenameWithProtocol)) {
                    filenameWithProtocol = 'file://' + filenameWithProtocol;
                }
                return '@media -sass-debug-info{filename{font-family:' +
                    filenameWithProtocol.replace(/([.:\/\\])/g, function(a) {
                        if (a == '\\') {
                            a = '\/';
                        }
                        return '\\' + a;
                    }) +
                    '}line{font-family:\\00003' + ctx.debugInfo.lineNumber + '}}\n';
            };

            module.exports = debugInfo;

        }, {}],
        53: [function(require, module, exports) {
            var Node = require("./node"),
                contexts = require("../contexts");

            var DetachedRuleset = function(ruleset, frames) {
                this.ruleset = ruleset;
                this.frames = frames;
            };
            DetachedRuleset.prototype = new Node();
            DetachedRuleset.prototype.type = "DetachedRuleset";
            DetachedRuleset.prototype.evalFirst = true;
            DetachedRuleset.prototype.accept = function(visitor) {
                this.ruleset = visitor.visit(this.ruleset);
            };
            DetachedRuleset.prototype.eval = function(context) {
                var frames = this.frames || context.frames.slice(0);
                return new DetachedRuleset(this.ruleset, frames);
            };
            DetachedRuleset.prototype.callEval = function(context) {
                return this.ruleset.eval(this.frames ? new contexts.Eval(context, this.frames.concat(context.frames)) : context);
            };
            module.exports = DetachedRuleset;

        }, { "../contexts": 10, "./node": 68 }],
        54: [function(require, module, exports) {
            var Node = require("./node"),
                unitConversions = require("../data/unit-conversions"),
                Unit = require("./unit"),
                Color = require("./color");

            //
            // A number with a unit
            //
            var Dimension = function(value, unit) {
                this.value = parseFloat(value);
                this.unit = (unit && unit instanceof Unit) ? unit :
                    new Unit(unit ? [unit] : undefined);
            };

            Dimension.prototype = new Node();
            Dimension.prototype.type = "Dimension";
            Dimension.prototype.accept = function(visitor) {
                this.unit = visitor.visit(this.unit);
            };
            Dimension.prototype.eval = function(context) {
                return this;
            };
            Dimension.prototype.toColor = function() {
                return new Color([this.value, this.value, this.value]);
            };
            Dimension.prototype.genCSS = function(context, output) {
                if ((context && context.strictUnits) && !this.unit.isSingular()) {
                    throw new Error("Multiple units in dimension. Correct the units or use the unit function. Bad unit: " + this.unit.toString());
                }

                var value = this.fround(context, this.value),
                    strValue = String(value);

                if (value !== 0 && value < 0.000001 && value > -0.000001) {
                    // would be output 1e-6 etc.
                    strValue = value.toFixed(20).replace(/0+$/, "");
                }

                if (context && context.compress) {
                    // Zero values doesn't need a unit
                    if (value === 0 && this.unit.isLength()) {
                        output.add(strValue);
                        return;
                    }

                    // Float values doesn't need a leading zero
                    if (value > 0 && value < 1) {
                        strValue = (strValue).substr(1);
                    }
                }

                output.add(strValue);
                this.unit.genCSS(context, output);
            };

            // In an operation between two Dimensions,
            // we default to the first Dimension's unit,
            // so `1px + 2` will yield `3px`.
            Dimension.prototype.operate = function(context, op, other) {
                /*jshint noempty:false */
                var value = this._operate(context, op, this.value, other.value),
                    unit = this.unit.clone();

                if (op === '+' || op === '-') {
                    if (unit.numerator.length === 0 && unit.denominator.length === 0) {
                        unit = other.unit.clone();
                        if (this.unit.backupUnit) {
                            unit.backupUnit = this.unit.backupUnit;
                        }
                    } else if (other.unit.numerator.length === 0 && unit.denominator.length === 0) {
                        // do nothing
                    } else {
                        other = other.convertTo(this.unit.usedUnits());

                        if (context.strictUnits && other.unit.toString() !== unit.toString()) {
                            throw new Error("Incompatible units. Change the units or use the unit function. Bad units: '" + unit.toString() +
                                "' and '" + other.unit.toString() + "'.");
                        }

                        value = this._operate(context, op, this.value, other.value);
                    }
                } else if (op === '*') {
                    unit.numerator = unit.numerator.concat(other.unit.numerator).sort();
                    unit.denominator = unit.denominator.concat(other.unit.denominator).sort();
                    unit.cancel();
                } else if (op === '/') {
                    unit.numerator = unit.numerator.concat(other.unit.denominator).sort();
                    unit.denominator = unit.denominator.concat(other.unit.numerator).sort();
                    unit.cancel();
                }
                return new Dimension(value, unit);
            };
            Dimension.prototype.compare = function(other) {
                var a, b;

                if (!(other instanceof Dimension)) {
                    return undefined;
                }

                if (this.unit.isEmpty() || other.unit.isEmpty()) {
                    a = this;
                    b = other;
                } else {
                    a = this.unify();
                    b = other.unify();
                    if (a.unit.compare(b.unit) !== 0) {
                        return undefined;
                    }
                }

                return Node.numericCompare(a.value, b.value);
            };
            Dimension.prototype.unify = function() {
                return this.convertTo({ length: 'px', duration: 's', angle: 'rad' });
            };
            Dimension.prototype.convertTo = function(conversions) {
                var value = this.value,
                    unit = this.unit.clone(),
                    i, groupName, group, targetUnit, derivedConversions = {},
                    applyUnit;

                if (typeof conversions === 'string') {
                    for (i in unitConversions) {
                        if (unitConversions[i].hasOwnProperty(conversions)) {
                            derivedConversions = {};
                            derivedConversions[i] = conversions;
                        }
                    }
                    conversions = derivedConversions;
                }
                applyUnit = function(atomicUnit, denominator) {
                    /* jshint loopfunc:true */
                    if (group.hasOwnProperty(atomicUnit)) {
                        if (denominator) {
                            value = value / (group[atomicUnit] / group[targetUnit]);
                        } else {
                            value = value * (group[atomicUnit] / group[targetUnit]);
                        }

                        return targetUnit;
                    }

                    return atomicUnit;
                };

                for (groupName in conversions) {
                    if (conversions.hasOwnProperty(groupName)) {
                        targetUnit = conversions[groupName];
                        group = unitConversions[groupName];

                        unit.map(applyUnit);
                    }
                }

                unit.cancel();

                return new Dimension(value, unit);
            };
            module.exports = Dimension;

        }, { "../data/unit-conversions": 13, "./color": 48, "./node": 68, "./unit": 77 }],
        55: [function(require, module, exports) {
            var Node = require("./node"),
                Selector = require("./selector"),
                Ruleset = require("./ruleset");

            var Directive = function(name, value, rules, index, currentFileInfo, debugInfo, isReferenced, isRooted) {
                var i;

                this.name = name;
                this.value = value;
                if (rules) {
                    if (Array.isArray(rules)) {
                        this.rules = rules;
                    } else {
                        this.rules = [rules];
                        this.rules[0].selectors = (new Selector([], null, null, this.index, currentFileInfo)).createEmptySelectors();
                    }
                    for (i = 0; i < this.rules.length; i++) {
                        this.rules[i].allowImports = true;
                    }
                }
                this.index = index;
                this.currentFileInfo = currentFileInfo;
                this.debugInfo = debugInfo;
                this.isReferenced = isReferenced;
                this.isRooted = isRooted || false;
            };

            Directive.prototype = new Node();
            Directive.prototype.type = "Directive";
            Directive.prototype.accept = function(visitor) {
                var value = this.value,
                    rules = this.rules;
                if (rules) {
                    this.rules = visitor.visitArray(rules);
                }
                if (value) {
                    this.value = visitor.visit(value);
                }
            };
            Directive.prototype.isRulesetLike = function() {
                return this.rules || !this.isCharset();
            };
            Directive.prototype.isCharset = function() {
                return "@charset" === this.name;
            };
            Directive.prototype.genCSS = function(context, output) {
                var value = this.value,
                    rules = this.rules;
                output.add(this.name, this.currentFileInfo, this.index);
                if (value) {
                    output.add(' ');
                    value.genCSS(context, output);
                }
                if (rules) {
                    this.outputRuleset(context, output, rules);
                } else {
                    output.add(';');
                }
            };
            Directive.prototype.eval = function(context) {
                var mediaPathBackup, mediaBlocksBackup, value = this.value,
                    rules = this.rules;

                //media stored inside other directive should not bubble over it
                //backpup media bubbling information
                mediaPathBackup = context.mediaPath;
                mediaBlocksBackup = context.mediaBlocks;
                //deleted media bubbling information
                context.mediaPath = [];
                context.mediaBlocks = [];

                if (value) {
                    value = value.eval(context);
                }
                if (rules) {
                    // assuming that there is only one rule at this point - that is how parser constructs the rule
                    rules = [rules[0].eval(context)];
                    rules[0].root = true;
                }
                //restore media bubbling information
                context.mediaPath = mediaPathBackup;
                context.mediaBlocks = mediaBlocksBackup;

                return new Directive(this.name, value, rules,
                    this.index, this.currentFileInfo, this.debugInfo, this.isReferenced, this.isRooted);
            };
            Directive.prototype.variable = function(name) {
                if (this.rules) {
                    // assuming that there is only one rule at this point - that is how parser constructs the rule
                    return Ruleset.prototype.variable.call(this.rules[0], name);
                }
            };
            Directive.prototype.find = function() {
                if (this.rules) {
                    // assuming that there is only one rule at this point - that is how parser constructs the rule
                    return Ruleset.prototype.find.apply(this.rules[0], arguments);
                }
            };
            Directive.prototype.rulesets = function() {
                if (this.rules) {
                    // assuming that there is only one rule at this point - that is how parser constructs the rule
                    return Ruleset.prototype.rulesets.apply(this.rules[0]);
                }
            };
            Directive.prototype.markReferenced = function() {
                var i, rules;
                this.isReferenced = true;
                if (this.rules) {
                    rules = this.rules;
                    for (i = 0; i < rules.length; i++) {
                        if (rules[i].markReferenced) {
                            rules[i].markReferenced();
                        }
                    }
                }
            };
            Directive.prototype.getIsReferenced = function() {
                return !this.currentFileInfo || !this.currentFileInfo.reference || this.isReferenced;
            };
            Directive.prototype.outputRuleset = function(context, output, rules) {
                var ruleCnt = rules.length,
                    i;
                context.tabLevel = (context.tabLevel | 0) + 1;

                // Compressed
                if (context.compress) {
                    output.add('{');
                    for (i = 0; i < ruleCnt; i++) {
                        rules[i].genCSS(context, output);
                    }
                    output.add('}');
                    context.tabLevel--;
                    return;
                }

                // Non-compressed
                var tabSetStr = '\n' + Array(context.tabLevel).join("  "),
                    tabRuleStr = tabSetStr + "  ";
                if (!ruleCnt) {
                    output.add(" {" + tabSetStr + '}');
                } else {
                    output.add(" {" + tabRuleStr);
                    rules[0].genCSS(context, output);
                    for (i = 1; i < ruleCnt; i++) {
                        output.add(tabRuleStr);
                        rules[i].genCSS(context, output);
                    }
                    output.add(tabSetStr + '}');
                }

                context.tabLevel--;
            };
            module.exports = Directive;

        }, { "./node": 68, "./ruleset": 74, "./selector": 75 }],
        56: [function(require, module, exports) {
            var Node = require("./node"),
                Paren = require("./paren"),
                Combinator = require("./combinator");

            var Element = function(combinator, value, index, currentFileInfo) {
                this.combinator = combinator instanceof Combinator ?
                    combinator : new Combinator(combinator);

                if (typeof value === 'string') {
                    this.value = value.trim();
                } else if (value) {
                    this.value = value;
                } else {
                    this.value = "";
                }
                this.index = index;
                this.currentFileInfo = currentFileInfo;
            };
            Element.prototype = new Node();
            Element.prototype.type = "Element";
            Element.prototype.accept = function(visitor) {
                var value = this.value;
                this.combinator = visitor.visit(this.combinator);
                if (typeof value === "object") {
                    this.value = visitor.visit(value);
                }
            };
            Element.prototype.eval = function(context) {
                return new Element(this.combinator,
                    this.value.eval ? this.value.eval(context) : this.value,
                    this.index,
                    this.currentFileInfo);
            };
            Element.prototype.genCSS = function(context, output) {
                output.add(this.toCSS(context), this.currentFileInfo, this.index);
            };
            Element.prototype.toCSS = function(context) {
                context = context || {};
                var value = this.value,
                    firstSelector = context.firstSelector;
                if (value instanceof Paren) {
                    // selector in parens should not be affected by outer selector
                    // flags (breaks only interpolated selectors - see #1973)
                    context.firstSelector = true;
                }
                value = value.toCSS ? value.toCSS(context) : value;
                context.firstSelector = firstSelector;
                if (value === '' && this.combinator.value.charAt(0) === '&') {
                    return '';
                } else {
                    return this.combinator.toCSS(context) + value;
                }
            };
            module.exports = Element;

        }, { "./combinator": 49, "./node": 68, "./paren": 70 }],
        57: [function(require, module, exports) {
            var Node = require("./node"),
                Paren = require("./paren"),
                Comment = require("./comment");

            var Expression = function(value) {
                this.value = value;
                if (!value) {
                    throw new Error("Expression requires an array parameter");
                }
            };
            Expression.prototype = new Node();
            Expression.prototype.type = "Expression";
            Expression.prototype.accept = function(visitor) {
                this.value = visitor.visitArray(this.value);
            };
            Expression.prototype.eval = function(context) {
                var returnValue,
                    inParenthesis = this.parens && !this.parensInOp,
                    doubleParen = false;
                if (inParenthesis) {
                    context.inParenthesis();
                }
                if (this.value.length > 1) {
                    returnValue = new Expression(this.value.map(function(e) {
                        return e.eval(context);
                    }));
                } else if (this.value.length === 1) {
                    if (this.value[0].parens && !this.value[0].parensInOp) {
                        doubleParen = true;
                    }
                    returnValue = this.value[0].eval(context);
                } else {
                    returnValue = this;
                }
                if (inParenthesis) {
                    context.outOfParenthesis();
                }
                if (this.parens && this.parensInOp && !(context.isMathOn()) && !doubleParen) {
                    returnValue = new Paren(returnValue);
                }
                return returnValue;
            };
            Expression.prototype.genCSS = function(context, output) {
                for (var i = 0; i < this.value.length; i++) {
                    this.value[i].genCSS(context, output);
                    if (i + 1 < this.value.length) {
                        output.add(" ");
                    }
                }
            };
            Expression.prototype.throwAwayComments = function() {
                this.value = this.value.filter(function(v) {
                    return !(v instanceof Comment);
                });
            };
            module.exports = Expression;

        }, { "./comment": 50, "./node": 68, "./paren": 70 }],
        58: [function(require, module, exports) {
            var Node = require("./node");

            var Extend = function Extend(selector, option, index) {
                this.selector = selector;
                this.option = option;
                this.index = index;
                this.object_id = Extend.next_id++;
                this.parent_ids = [this.object_id];

                switch (option) {
                    case "all":
                        this.allowBefore = true;
                        this.allowAfter = true;
                        break;
                    default:
                        this.allowBefore = false;
                        this.allowAfter = false;
                        break;
                }
            };
            Extend.next_id = 0;

            Extend.prototype = new Node();
            Extend.prototype.type = "Extend";
            Extend.prototype.accept = function(visitor) {
                this.selector = visitor.visit(this.selector);
            };
            Extend.prototype.eval = function(context) {
                return new Extend(this.selector.eval(context), this.option, this.index);
            };
            Extend.prototype.clone = function(context) {
                return new Extend(this.selector, this.option, this.index);
            };
            Extend.prototype.findSelfSelectors = function(selectors) {
                var selfElements = [],
                    i,
                    selectorElements;

                for (i = 0; i < selectors.length; i++) {
                    selectorElements = selectors[i].elements;
                    // duplicate the logic in genCSS function inside the selector node.
                    // future TODO - move both logics into the selector joiner visitor
                    if (i > 0 && selectorElements.length && selectorElements[0].combinator.value === "") {
                        selectorElements[0].combinator.value = ' ';
                    }
                    selfElements = selfElements.concat(selectors[i].elements);
                }

                this.selfSelectors = [{ elements: selfElements }];
            };
            module.exports = Extend;

        }, { "./node": 68 }],
        59: [function(require, module, exports) {
            var Node = require("./node"),
                Media = require("./media"),
                URL = require("./url"),
                Quoted = require("./quoted"),
                Ruleset = require("./ruleset"),
                Anonymous = require("./anonymous");

            //
            // CSS @import node
            //
            // The general strategy here is that we don't want to wait
            // for the parsing to be completed, before we start importing
            // the file. That's because in the context of a browser,
            // most of the time will be spent waiting for the server to respond.
            //
            // On creation, we push the import path to our import queue, though
            // `import,push`, we also pass it a callback, which it'll call once
            // the file has been fetched, and parsed.
            //
            var Import = function(path, features, options, index, currentFileInfo) {
                this.options = options;
                this.index = index;
                this.path = path;
                this.features = features;
                this.currentFileInfo = currentFileInfo;

                if (this.options.less !== undefined || this.options.inline) {
                    this.css = !this.options.less || this.options.inline;
                } else {
                    var pathValue = this.getPath();
                    if (pathValue && /[#\.\&\?\/]css([\?;].*)?$/.test(pathValue)) {
                        this.css = true;
                    }
                }
            };

            //
            // The actual import node doesn't return anything, when converted to CSS.
            // The reason is that it's used at the evaluation stage, so that the rules
            // it imports can be treated like any other rules.
            //
            // In `eval`, we make sure all Import nodes get evaluated, recursively, so
            // we end up with a flat structure, which can easily be imported in the parent
            // ruleset.
            //
            Import.prototype = new Node();
            Import.prototype.type = "Import";
            Import.prototype.accept = function(visitor) {
                if (this.features) {
                    this.features = visitor.visit(this.features);
                }
                this.path = visitor.visit(this.path);
                if (!this.options.plugin && !this.options.inline && this.root) {
                    this.root = visitor.visit(this.root);
                }
            };
            Import.prototype.genCSS = function(context, output) {
                if (this.css && this.path.currentFileInfo.reference === undefined) {
                    output.add("@import ", this.currentFileInfo, this.index);
                    this.path.genCSS(context, output);
                    if (this.features) {
                        output.add(" ");
                        this.features.genCSS(context, output);
                    }
                    output.add(';');
                }
            };
            Import.prototype.getPath = function() {
                return (this.path instanceof URL) ?
                    this.path.value.value : this.path.value;
            };
            Import.prototype.isVariableImport = function() {
                var path = this.path;
                if (path instanceof URL) {
                    path = path.value;
                }
                if (path instanceof Quoted) {
                    return path.containsVariables();
                }

                return true;
            };
            Import.prototype.evalForImport = function(context) {
                var path = this.path;

                if (path instanceof URL) {
                    path = path.value;
                }

                return new Import(path.eval(context), this.features, this.options, this.index, this.currentFileInfo);
            };
            Import.prototype.evalPath = function(context) {
                var path = this.path.eval(context);
                var rootpath = this.currentFileInfo && this.currentFileInfo.rootpath;

                if (!(path instanceof URL)) {
                    if (rootpath) {
                        var pathValue = path.value;
                        // Add the base path if the import is relative
                        if (pathValue && context.isPathRelative(pathValue)) {
                            path.value = rootpath + pathValue;
                        }
                    }
                    path.value = context.normalizePath(path.value);
                }

                return path;
            };
            Import.prototype.eval = function(context) {
                var ruleset, registry,
                    features = this.features && this.features.eval(context);

                if (this.options.plugin) {
                    registry = context.frames[0] && context.frames[0].functionRegistry;
                    if (registry && this.root && this.root.functions) {
                        registry.addMultiple(this.root.functions);
                    }
                    return [];
                }

                if (this.skip) {
                    if (typeof this.skip === "function") {
                        this.skip = this.skip();
                    }
                    if (this.skip) {
                        return [];
                    }
                }

                if (this.options.inline) {
                    var contents = new Anonymous(this.root, 0, { filename: this.importedFilename }, true, true);
                    return this.features ? new Media([contents], this.features.value) : [contents];
                } else if (this.css) {
                    var newImport = new Import(this.evalPath(context), features, this.options, this.index);
                    if (!newImport.css && this.error) {
                        throw this.error;
                    }
                    return newImport;
                } else {
                    ruleset = new Ruleset(null, this.root.rules.slice(0));

                    ruleset.evalImports(context);

                    return this.features ? new Media(ruleset.rules, this.features.value) : ruleset.rules;
                }
            };
            module.exports = Import;

        }, { "./anonymous": 44, "./media": 64, "./node": 68, "./quoted": 71, "./ruleset": 74, "./url": 78 }],
        60: [function(require, module, exports) {
            var tree = {};

            tree.Node = require('./node');
            tree.Alpha = require('./alpha');
            tree.Color = require('./color');
            tree.Directive = require('./directive');
            tree.DetachedRuleset = require('./detached-ruleset');
            tree.Operation = require('./operation');
            tree.Dimension = require('./dimension');
            tree.Unit = require('./unit');
            tree.Keyword = require('./keyword');
            tree.Variable = require('./variable');
            tree.Ruleset = require('./ruleset');
            tree.Element = require('./element');
            tree.Attribute = require('./attribute');
            tree.Combinator = require('./combinator');
            tree.Selector = require('./selector');
            tree.Quoted = require('./quoted');
            tree.Expression = require('./expression');
            tree.Rule = require('./rule');
            tree.Call = require('./call');
            tree.URL = require('./url');
            tree.Import = require('./import');
            tree.mixin = {
                Call: require('./mixin-call'),
                Definition: require('./mixin-definition')
            };
            tree.Comment = require('./comment');
            tree.Anonymous = require('./anonymous');
            tree.Value = require('./value');
            tree.JavaScript = require('./javascript');
            tree.Assignment = require('./assignment');
            tree.Condition = require('./condition');
            tree.Paren = require('./paren');
            tree.Media = require('./media');
            tree.UnicodeDescriptor = require('./unicode-descriptor');
            tree.Negative = require('./negative');
            tree.Extend = require('./extend');
            tree.RulesetCall = require('./ruleset-call');

            module.exports = tree;

        }, { "./alpha": 43, "./anonymous": 44, "./assignment": 45, "./attribute": 46, "./call": 47, "./color": 48, "./combinator": 49, "./comment": 50, "./condition": 51, "./detached-ruleset": 53, "./dimension": 54, "./directive": 55, "./element": 56, "./expression": 57, "./extend": 58, "./import": 59, "./javascript": 61, "./keyword": 63, "./media": 64, "./mixin-call": 65, "./mixin-definition": 66, "./negative": 67, "./node": 68, "./operation": 69, "./paren": 70, "./quoted": 71, "./rule": 72, "./ruleset": 74, "./ruleset-call": 73, "./selector": 75, "./unicode-descriptor": 76, "./unit": 77, "./url": 78, "./value": 79, "./variable": 80 }],
        61: [function(require, module, exports) {
            var JsEvalNode = require("./js-eval-node"),
                Dimension = require("./dimension"),
                Quoted = require("./quoted"),
                Anonymous = require("./anonymous");

            var JavaScript = function(string, escaped, index, currentFileInfo) {
                this.escaped = escaped;
                this.expression = string;
                this.index = index;
                this.currentFileInfo = currentFileInfo;
            };
            JavaScript.prototype = new JsEvalNode();
            JavaScript.prototype.type = "JavaScript";
            JavaScript.prototype.eval = function(context) {
                var result = this.evaluateJavaScript(this.expression, context);

                if (typeof result === 'number') {
                    return new Dimension(result);
                } else if (typeof result === 'string') {
                    return new Quoted('"' + result + '"', result, this.escaped, this.index);
                } else if (Array.isArray(result)) {
                    return new Anonymous(result.join(', '));
                } else {
                    return new Anonymous(result);
                }
            };

            module.exports = JavaScript;

        }, { "./anonymous": 44, "./dimension": 54, "./js-eval-node": 62, "./quoted": 71 }],
        62: [function(require, module, exports) {
            var Node = require("./node"),
                Variable = require("./variable");

            var JsEvalNode = function() {};
            JsEvalNode.prototype = new Node();

            JsEvalNode.prototype.evaluateJavaScript = function(expression, context) {
                var result,
                    that = this,
                    evalContext = {};

                if (context.javascriptEnabled !== undefined && !context.javascriptEnabled) {
                    throw {
                        message: "You are using JavaScript, which has been disabled.",
                        filename: this.currentFileInfo.filename,
                        index: this.index
                    };
                }

                expression = expression.replace(/@\{([\w-]+)\}/g, function(_, name) {
                    return that.jsify(new Variable('@' + name, that.index, that.currentFileInfo).eval(context));
                });

                try {
                    expression = new Function('return (' + expression + ')');
                } catch (e) {
                    throw {
                        message: "JavaScript evaluation error: " + e.message + " from `" + expression + "`",
                        filename: this.currentFileInfo.filename,
                        index: this.index
                    };
                }

                var variables = context.frames[0].variables();
                for (var k in variables) {
                    if (variables.hasOwnProperty(k)) {
                        /*jshint loopfunc:true */
                        evalContext[k.slice(1)] = {
                            value: variables[k].value,
                            toJS: function() {
                                return this.value.eval(context).toCSS();
                            }
                        };
                    }
                }

                try {
                    result = expression.call(evalContext);
                } catch (e) {
                    throw {
                        message: "JavaScript evaluation error: '" + e.name + ': ' + e.message.replace(/["]/g, "'") + "'",
                        filename: this.currentFileInfo.filename,
                        index: this.index
                    };
                }
                return result;
            };
            JsEvalNode.prototype.jsify = function(obj) {
                if (Array.isArray(obj.value) && (obj.value.length > 1)) {
                    return '[' + obj.value.map(function(v) { return v.toCSS(); }).join(', ') + ']';
                } else {
                    return obj.toCSS();
                }
            };

            module.exports = JsEvalNode;

        }, { "./node": 68, "./variable": 80 }],
        63: [function(require, module, exports) {
            var Node = require("./node");

            var Keyword = function(value) { this.value = value; };
            Keyword.prototype = new Node();
            Keyword.prototype.type = "Keyword";
            Keyword.prototype.genCSS = function(context, output) {
                if (this.value === '%') { throw { type: "Syntax", message: "Invalid % without number" }; }
                output.add(this.value);
            };

            Keyword.True = new Keyword('true');
            Keyword.False = new Keyword('false');

            module.exports = Keyword;

        }, { "./node": 68 }],
        64: [function(require, module, exports) {
            var Ruleset = require("./ruleset"),
                Value = require("./value"),
                Selector = require("./selector"),
                Anonymous = require("./anonymous"),
                Expression = require("./expression"),
                Directive = require("./directive");

            var Media = function(value, features, index, currentFileInfo) {
                this.index = index;
                this.currentFileInfo = currentFileInfo;

                var selectors = (new Selector([], null, null, this.index, this.currentFileInfo)).createEmptySelectors();

                this.features = new Value(features);
                this.rules = [new Ruleset(selectors, value)];
                this.rules[0].allowImports = true;
            };
            Media.prototype = new Directive();
            Media.prototype.type = "Media";
            Media.prototype.isRulesetLike = true;
            Media.prototype.accept = function(visitor) {
                if (this.features) {
                    this.features = visitor.visit(this.features);
                }
                if (this.rules) {
                    this.rules = visitor.visitArray(this.rules);
                }
            };
            Media.prototype.genCSS = function(context, output) {
                output.add('@media ', this.currentFileInfo, this.index);
                this.features.genCSS(context, output);
                this.outputRuleset(context, output, this.rules);
            };
            Media.prototype.eval = function(context) {
                if (!context.mediaBlocks) {
                    context.mediaBlocks = [];
                    context.mediaPath = [];
                }

                var media = new Media(null, [], this.index, this.currentFileInfo);
                if (this.debugInfo) {
                    this.rules[0].debugInfo = this.debugInfo;
                    media.debugInfo = this.debugInfo;
                }
                var strictMathBypass = false;
                if (!context.strictMath) {
                    strictMathBypass = true;
                    context.strictMath = true;
                }
                try {
                    media.features = this.features.eval(context);
                } finally {
                    if (strictMathBypass) {
                        context.strictMath = false;
                    }
                }

                context.mediaPath.push(media);
                context.mediaBlocks.push(media);

                this.rules[0].functionRegistry = context.frames[0].functionRegistry.inherit();
                context.frames.unshift(this.rules[0]);
                media.rules = [this.rules[0].eval(context)];
                context.frames.shift();

                context.mediaPath.pop();

                return context.mediaPath.length === 0 ? media.evalTop(context) :
                    media.evalNested(context);
            };
            Media.prototype.evalTop = function(context) {
                var result = this;

                // Render all dependent Media blocks.
                if (context.mediaBlocks.length > 1) {
                    var selectors = (new Selector([], null, null, this.index, this.currentFileInfo)).createEmptySelectors();
                    result = new Ruleset(selectors, context.mediaBlocks);
                    result.multiMedia = true;
                }

                delete context.mediaBlocks;
                delete context.mediaPath;

                return result;
            };
            Media.prototype.evalNested = function(context) {
                var i, value,
                    path = context.mediaPath.concat([this]);

                // Extract the media-query conditions separated with `,` (OR).
                for (i = 0; i < path.length; i++) {
                    value = path[i].features instanceof Value ?
                        path[i].features.value : path[i].features;
                    path[i] = Array.isArray(value) ? value : [value];
                }

                // Trace all permutations to generate the resulting media-query.
                //
                // (a, b and c) with nested (d, e) ->
                //    a and d
                //    a and e
                //    b and c and d
                //    b and c and e
                this.features = new Value(this.permute(path).map(function(path) {
                    path = path.map(function(fragment) {
                        return fragment.toCSS ? fragment : new Anonymous(fragment);
                    });

                    for (i = path.length - 1; i > 0; i--) {
                        path.splice(i, 0, new Anonymous("and"));
                    }

                    return new Expression(path);
                }));

                // Fake a tree-node that doesn't output anything.
                return new Ruleset([], []);
            };
            Media.prototype.permute = function(arr) {
                if (arr.length === 0) {
                    return [];
                } else if (arr.length === 1) {
                    return arr[0];
                } else {
                    var result = [];
                    var rest = this.permute(arr.slice(1));
                    for (var i = 0; i < rest.length; i++) {
                        for (var j = 0; j < arr[0].length; j++) {
                            result.push([arr[0][j]].concat(rest[i]));
                        }
                    }
                    return result;
                }
            };
            Media.prototype.bubbleSelectors = function(selectors) {
                if (!selectors) {
                    return;
                }
                this.rules = [new Ruleset(selectors.slice(0), [this.rules[0]])];
            };
            module.exports = Media;

        }, { "./anonymous": 44, "./directive": 55, "./expression": 57, "./ruleset": 74, "./selector": 75, "./value": 79 }],
        65: [function(require, module, exports) {
            var Node = require("./node"),
                Selector = require("./selector"),
                MixinDefinition = require("./mixin-definition"),
                defaultFunc = require("../functions/default");

            var MixinCall = function(elements, args, index, currentFileInfo, important) {
                this.selector = new Selector(elements);
                this.arguments = (args && args.length) ? args : null;
                this.index = index;
                this.currentFileInfo = currentFileInfo;
                this.important = important;
            };
            MixinCall.prototype = new Node();
            MixinCall.prototype.type = "MixinCall";
            MixinCall.prototype.accept = function(visitor) {
                if (this.selector) {
                    this.selector = visitor.visit(this.selector);
                }
                if (this.arguments) {
                    this.arguments = visitor.visitArray(this.arguments);
                }
            };
            MixinCall.prototype.eval = function(context) {
                var mixins, mixin, mixinPath, args, rules = [],
                    match = false,
                    i, m, f, isRecursive, isOneFound, rule,
                    candidates = [],
                    candidate, conditionResult = [],
                    defaultResult, defFalseEitherCase = -1,
                    defNone = 0,
                    defTrue = 1,
                    defFalse = 2,
                    count, originalRuleset, noArgumentsFilter;

                function calcDefGroup(mixin, mixinPath) {
                    var p, namespace;

                    for (f = 0; f < 2; f++) {
                        conditionResult[f] = true;
                        defaultFunc.value(f);
                        for (p = 0; p < mixinPath.length && conditionResult[f]; p++) {
                            namespace = mixinPath[p];
                            if (namespace.matchCondition) {
                                conditionResult[f] = conditionResult[f] && namespace.matchCondition(null, context);
                            }
                        }
                        if (mixin.matchCondition) {
                            conditionResult[f] = conditionResult[f] && mixin.matchCondition(args, context);
                        }
                    }
                    if (conditionResult[0] || conditionResult[1]) {
                        if (conditionResult[0] != conditionResult[1]) {
                            return conditionResult[1] ?
                                defTrue : defFalse;
                        }

                        return defNone;
                    }
                    return defFalseEitherCase;
                }

                args = this.arguments && this.arguments.map(function(a) {
                    return { name: a.name, value: a.value.eval(context) };
                });

                noArgumentsFilter = function(rule) { return rule.matchArgs(null, context); };

                for (i = 0; i < context.frames.length; i++) {
                    if ((mixins = context.frames[i].find(this.selector, null, noArgumentsFilter)).length > 0) {
                        isOneFound = true;

                        // To make `default()` function independent of definition order we have two "subpasses" here.
                        // At first we evaluate each guard *twice* (with `default() == true` and `default() == false`),
                        // and build candidate list with corresponding flags. Then, when we know all possible matches,
                        // we make a final decision.

                        for (m = 0; m < mixins.length; m++) {
                            mixin = mixins[m].rule;
                            mixinPath = mixins[m].path;
                            isRecursive = false;
                            for (f = 0; f < context.frames.length; f++) {
                                if ((!(mixin instanceof MixinDefinition)) && mixin === (context.frames[f].originalRuleset || context.frames[f])) {
                                    isRecursive = true;
                                    break;
                                }
                            }
                            if (isRecursive) {
                                continue;
                            }

                            if (mixin.matchArgs(args, context)) {
                                candidate = { mixin: mixin, group: calcDefGroup(mixin, mixinPath) };

                                if (candidate.group !== defFalseEitherCase) {
                                    candidates.push(candidate);
                                }

                                match = true;
                            }
                        }

                        defaultFunc.reset();

                        count = [0, 0, 0];
                        for (m = 0; m < candidates.length; m++) {
                            count[candidates[m].group]++;
                        }

                        if (count[defNone] > 0) {
                            defaultResult = defFalse;
                        } else {
                            defaultResult = defTrue;
                            if ((count[defTrue] + count[defFalse]) > 1) {
                                throw {
                                    type: 'Runtime',
                                    message: 'Ambiguous use of `default()` found when matching for `' + this.format(args) + '`',
                                    index: this.index,
                                    filename: this.currentFileInfo.filename
                                };
                            }
                        }

                        for (m = 0; m < candidates.length; m++) {
                            candidate = candidates[m].group;
                            if ((candidate === defNone) || (candidate === defaultResult)) {
                                try {
                                    mixin = candidates[m].mixin;
                                    if (!(mixin instanceof MixinDefinition)) {
                                        originalRuleset = mixin.originalRuleset || mixin;
                                        mixin = new MixinDefinition("", [], mixin.rules, null, false);
                                        mixin.originalRuleset = originalRuleset;
                                    }
                                    Array.prototype.push.apply(
                                        rules, mixin.evalCall(context, args, this.important).rules);
                                } catch (e) {
                                    throw { message: e.message, index: this.index, filename: this.currentFileInfo.filename, stack: e.stack };
                                }
                            }
                        }

                        if (match) {
                            if (!this.currentFileInfo || !this.currentFileInfo.reference) {
                                for (i = 0; i < rules.length; i++) {
                                    rule = rules[i];
                                    if (rule.markReferenced) {
                                        rule.markReferenced();
                                    }
                                }
                            }
                            return rules;
                        }
                    }
                }
                if (isOneFound) {
                    throw {
                        type: 'Runtime',
                        message: 'No matching definition was found for `' + this.format(args) + '`',
                        index: this.index,
                        filename: this.currentFileInfo.filename
                    };
                } else {
                    throw {
                        type: 'Name',
                        message: this.selector.toCSS().trim() + " is undefined",
                        index: this.index,
                        filename: this.currentFileInfo.filename
                    };
                }
            };
            MixinCall.prototype.format = function(args) {
                return this.selector.toCSS().trim() + '(' +
                    (args ? args.map(function(a) {
                        var argValue = "";
                        if (a.name) {
                            argValue += a.name + ":";
                        }
                        if (a.value.toCSS) {
                            argValue += a.value.toCSS();
                        } else {
                            argValue += "???";
                        }
                        return argValue;
                    }).join(', ') : "") + ")";
            };
            module.exports = MixinCall;

        }, { "../functions/default": 19, "./mixin-definition": 66, "./node": 68, "./selector": 75 }],
        66: [function(require, module, exports) {
            var Selector = require("./selector"),
                Element = require("./element"),
                Ruleset = require("./ruleset"),
                Rule = require("./rule"),
                Expression = require("./expression"),
                contexts = require("../contexts");

            var Definition = function(name, params, rules, condition, variadic, frames) {
                this.name = name;
                this.selectors = [new Selector([new Element(null, name, this.index, this.currentFileInfo)])];
                this.params = params;
                this.condition = condition;
                this.variadic = variadic;
                this.arity = params.length;
                this.rules = rules;
                this._lookups = {};
                this.required = params.reduce(function(count, p) {
                    if (!p.name || (p.name && !p.value)) {
                        return count + 1;
                    } else {
                        return count;
                    }
                }, 0);
                this.frames = frames;
            };
            Definition.prototype = new Ruleset();
            Definition.prototype.type = "MixinDefinition";
            Definition.prototype.evalFirst = true;
            Definition.prototype.accept = function(visitor) {
                if (this.params && this.params.length) {
                    this.params = visitor.visitArray(this.params);
                }
                this.rules = visitor.visitArray(this.rules);
                if (this.condition) {
                    this.condition = visitor.visit(this.condition);
                }
            };
            Definition.prototype.evalParams = function(context, mixinEnv, args, evaldArguments) {
                /*jshint boss:true */
                var frame = new Ruleset(null, null),
                    varargs, arg,
                    params = this.params.slice(0),
                    i, j, val, name, isNamedFound, argIndex, argsLength = 0;

                if (mixinEnv.frames && mixinEnv.frames[0] && mixinEnv.frames[0].functionRegistry) {
                    frame.functionRegistry = mixinEnv.frames[0].functionRegistry.inherit();
                }
                mixinEnv = new contexts.Eval(mixinEnv, [frame].concat(mixinEnv.frames));

                if (args) {
                    args = args.slice(0);
                    argsLength = args.length;

                    for (i = 0; i < argsLength; i++) {
                        arg = args[i];
                        if (name = (arg && arg.name)) {
                            isNamedFound = false;
                            for (j = 0; j < params.length; j++) {
                                if (!evaldArguments[j] && name === params[j].name) {
                                    evaldArguments[j] = arg.value.eval(context);
                                    frame.prependRule(new Rule(name, arg.value.eval(context)));
                                    isNamedFound = true;
                                    break;
                                }
                            }
                            if (isNamedFound) {
                                args.splice(i, 1);
                                i--;
                                continue;
                            } else {
                                throw {
                                    type: 'Runtime',
                                    message: "Named argument for " + this.name +
                                        ' ' + args[i].name + ' not found'
                                };
                            }
                        }
                    }
                }
                argIndex = 0;
                for (i = 0; i < params.length; i++) {
                    if (evaldArguments[i]) { continue; }

                    arg = args && args[argIndex];

                    if (name = params[i].name) {
                        if (params[i].variadic) {
                            varargs = [];
                            for (j = argIndex; j < argsLength; j++) {
                                varargs.push(args[j].value.eval(context));
                            }
                            frame.prependRule(new Rule(name, new Expression(varargs).eval(context)));
                        } else {
                            val = arg && arg.value;
                            if (val) {
                                val = val.eval(context);
                            } else if (params[i].value) {
                                val = params[i].value.eval(mixinEnv);
                                frame.resetCache();
                            } else {
                                throw {
                                    type: 'Runtime',
                                    message: "wrong number of arguments for " + this.name +
                                        ' (' + argsLength + ' for ' + this.arity + ')'
                                };
                            }

                            frame.prependRule(new Rule(name, val));
                            evaldArguments[i] = val;
                        }
                    }

                    if (params[i].variadic && args) {
                        for (j = argIndex; j < argsLength; j++) {
                            evaldArguments[j] = args[j].value.eval(context);
                        }
                    }
                    argIndex++;
                }

                return frame;
            };
            Definition.prototype.makeImportant = function() {
                var rules = !this.rules ? this.rules : this.rules.map(function(r) {
                    if (r.makeImportant) {
                        return r.makeImportant(true);
                    } else {
                        return r;
                    }
                });
                var result = new Definition(this.name, this.params, rules, this.condition, this.variadic, this.frames);
                return result;
            };
            Definition.prototype.eval = function(context) {
                return new Definition(this.name, this.params, this.rules, this.condition, this.variadic, this.frames || context.frames.slice(0));
            };
            Definition.prototype.evalCall = function(context, args, important) {
                var _arguments = [],
                    mixinFrames = this.frames ? this.frames.concat(context.frames) : context.frames,
                    frame = this.evalParams(context, new contexts.Eval(context, mixinFrames), args, _arguments),
                    rules, ruleset;

                frame.prependRule(new Rule('@arguments', new Expression(_arguments).eval(context)));

                rules = this.rules.slice(0);

                ruleset = new Ruleset(null, rules);
                ruleset.originalRuleset = this;
                ruleset = ruleset.eval(new contexts.Eval(context, [this, frame].concat(mixinFrames)));
                if (important) {
                    ruleset = ruleset.makeImportant();
                }
                return ruleset;
            };
            Definition.prototype.matchCondition = function(args, context) {
                if (this.condition && !this.condition.eval(
                        new contexts.Eval(context, [this.evalParams(context, /* the parameter variables*/
                                new contexts.Eval(context, this.frames ? this.frames.concat(context.frames) : context.frames), args, [])]
                            .concat(this.frames || []) // the parent namespace/mixin frames
                            .concat(context.frames)))) { // the current environment frames
                    return false;
                }
                return true;
            };
            Definition.prototype.matchArgs = function(args, context) {
                var argsLength = (args && args.length) || 0,
                    len;

                if (!this.variadic) {
                    if (argsLength < this.required) {
                        return false;
                    }
                    if (argsLength > this.params.length) {
                        return false;
                    }
                } else {
                    if (argsLength < (this.required - 1)) {
                        return false;
                    }
                }

                len = Math.min(argsLength, this.arity);

                for (var i = 0; i < len; i++) {
                    if (!this.params[i].name && !this.params[i].variadic) {
                        if (args[i].value.eval(context).toCSS() != this.params[i].value.eval(context).toCSS()) {
                            return false;
                        }
                    }
                }
                return true;
            };
            module.exports = Definition;

        }, { "../contexts": 10, "./element": 56, "./expression": 57, "./rule": 72, "./ruleset": 74, "./selector": 75 }],
        67: [function(require, module, exports) {
            var Node = require("./node"),
                Operation = require("./operation"),
                Dimension = require("./dimension");

            var Negative = function(node) {
                this.value = node;
            };
            Negative.prototype = new Node();
            Negative.prototype.type = "Negative";
            Negative.prototype.genCSS = function(context, output) {
                output.add('-');
                this.value.genCSS(context, output);
            };
            Negative.prototype.eval = function(context) {
                if (context.isMathOn()) {
                    return (new Operation('*', [new Dimension(-1), this.value])).eval(context);
                }
                return new Negative(this.value.eval(context));
            };
            module.exports = Negative;

        }, { "./dimension": 54, "./node": 68, "./operation": 69 }],
        68: [function(require, module, exports) {
            var Node = function() {};
            Node.prototype.toCSS = function(context) {
                var strs = [];
                this.genCSS(context, {
                    add: function(chunk, fileInfo, index) {
                        strs.push(chunk);
                    },
                    isEmpty: function() {
                        return strs.length === 0;
                    }
                });
                return strs.join('');
            };
            Node.prototype.genCSS = function(context, output) {
                output.add(this.value);
            };
            Node.prototype.accept = function(visitor) {
                this.value = visitor.visit(this.value);
            };
            Node.prototype.eval = function() { return this; };
            Node.prototype._operate = function(context, op, a, b) {
                switch (op) {
                    case '+':
                        return a + b;
                    case '-':
                        return a - b;
                    case '*':
                        return a * b;
                    case '/':
                        return a / b;
                }
            };
            Node.prototype.fround = function(context, value) {
                var precision = context && context.numPrecision;
                //add "epsilon" to ensure numbers like 1.000000005 (represented as 1.000000004999....) are properly rounded...
                return (precision == null) ? value : Number((value + 2e-16).toFixed(precision));
            };
            Node.compare = function(a, b) {
                /* returns:
                 -1: a < b
                 0: a = b
                 1: a > b
                 and *any* other value for a != b (e.g. undefined, NaN, -2 etc.) */

                if ((a.compare) &&
                    // for "symmetric results" force toCSS-based comparison
                    // of Quoted or Anonymous if either value is one of those
                    !(b.type === "Quoted" || b.type === "Anonymous")) {
                    return a.compare(b);
                } else if (b.compare) {
                    return -b.compare(a);
                } else if (a.type !== b.type) {
                    return undefined;
                }

                a = a.value;
                b = b.value;
                if (!Array.isArray(a)) {
                    return a === b ? 0 : undefined;
                }
                if (a.length !== b.length) {
                    return undefined;
                }
                for (var i = 0; i < a.length; i++) {
                    if (Node.compare(a[i], b[i]) !== 0) {
                        return undefined;
                    }
                }
                return 0;
            };

            Node.numericCompare = function(a, b) {
                return a < b ? -1 :
                    a === b ? 0 :
                    a > b ? 1 : undefined;
            };
            module.exports = Node;

        }, {}],
        69: [function(require, module, exports) {
            var Node = require("./node"),
                Color = require("./color"),
                Dimension = require("./dimension");

            var Operation = function(op, operands, isSpaced) {
                this.op = op.trim();
                this.operands = operands;
                this.isSpaced = isSpaced;
            };
            Operation.prototype = new Node();
            Operation.prototype.type = "Operation";
            Operation.prototype.accept = function(visitor) {
                this.operands = visitor.visit(this.operands);
            };
            Operation.prototype.eval = function(context) {
                var a = this.operands[0].eval(context),
                    b = this.operands[1].eval(context);

                if (context.isMathOn()) {
                    if (a instanceof Dimension && b instanceof Color) {
                        a = a.toColor();
                    }
                    if (b instanceof Dimension && a instanceof Color) {
                        b = b.toColor();
                    }
                    if (!a.operate) {
                        throw {
                            type: "Operation",
                            message: "Operation on an invalid type"
                        };
                    }

                    return a.operate(context, this.op, b);
                } else {
                    return new Operation(this.op, [a, b], this.isSpaced);
                }
            };
            Operation.prototype.genCSS = function(context, output) {
                this.operands[0].genCSS(context, output);
                if (this.isSpaced) {
                    output.add(" ");
                }
                output.add(this.op);
                if (this.isSpaced) {
                    output.add(" ");
                }
                this.operands[1].genCSS(context, output);
            };

            module.exports = Operation;

        }, { "./color": 48, "./dimension": 54, "./node": 68 }],
        70: [function(require, module, exports) {
            var Node = require("./node");

            var Paren = function(node) {
                this.value = node;
            };
            Paren.prototype = new Node();
            Paren.prototype.type = "Paren";
            Paren.prototype.genCSS = function(context, output) {
                output.add('(');
                this.value.genCSS(context, output);
                output.add(')');
            };
            Paren.prototype.eval = function(context) {
                return new Paren(this.value.eval(context));
            };
            module.exports = Paren;

        }, { "./node": 68 }],
        71: [function(require, module, exports) {
            var Node = require("./node"),
                JsEvalNode = require("./js-eval-node"),
                Variable = require("./variable");

            var Quoted = function(str, content, escaped, index, currentFileInfo) {
                this.escaped = (escaped == null) ? true : escaped;
                this.value = content || '';
                this.quote = str.charAt(0);
                this.index = index;
                this.currentFileInfo = currentFileInfo;
            };
            Quoted.prototype = new JsEvalNode();
            Quoted.prototype.type = "Quoted";
            Quoted.prototype.genCSS = function(context, output) {
                if (!this.escaped) {
                    output.add(this.quote, this.currentFileInfo, this.index);
                }
                output.add(this.value);
                if (!this.escaped) {
                    output.add(this.quote);
                }
            };
            Quoted.prototype.containsVariables = function() {
                return this.value.match(/(`([^`]+)`)|@\{([\w-]+)\}/);
            };
            Quoted.prototype.eval = function(context) {
                var that = this,
                    value = this.value;
                var javascriptReplacement = function(_, exp) {
                    return String(that.evaluateJavaScript(exp, context));
                };
                var interpolationReplacement = function(_, name) {
                    var v = new Variable('@' + name, that.index, that.currentFileInfo).eval(context, true);
                    return (v instanceof Quoted) ? v.value : v.toCSS();
                };

                function iterativeReplace(value, regexp, replacementFnc) {
                    var evaluatedValue = value;
                    do {
                        value = evaluatedValue;
                        evaluatedValue = value.replace(regexp, replacementFnc);
                    } while (value !== evaluatedValue);
                    return evaluatedValue;
                }
                value = iterativeReplace(value, /`([^`]+)`/g, javascriptReplacement);
                value = iterativeReplace(value, /@\{([\w-]+)\}/g, interpolationReplacement);
                return new Quoted(this.quote + value + this.quote, value, this.escaped, this.index, this.currentFileInfo);
            };
            Quoted.prototype.compare = function(other) {
                // when comparing quoted strings allow the quote to differ
                if (other.type === "Quoted" && !this.escaped && !other.escaped) {
                    return Node.numericCompare(this.value, other.value);
                } else {
                    return other.toCSS && this.toCSS() === other.toCSS() ? 0 : undefined;
                }
            };
            module.exports = Quoted;

        }, { "./js-eval-node": 62, "./node": 68, "./variable": 80 }],
        72: [function(require, module, exports) {
            var Node = require("./node"),
                Value = require("./value"),
                Keyword = require("./keyword");

            var Rule = function(name, value, important, merge, index, currentFileInfo, inline, variable) {
                this.name = name;
                this.value = (value instanceof Node) ? value : new Value([value]); //value instanceof tree.Value || value instanceof tree.Ruleset ??
                this.important = important ? ' ' + important.trim() : '';
                this.merge = merge;
                this.index = index;
                this.currentFileInfo = currentFileInfo;
                this.inline = inline || false;
                this.variable = (variable !== undefined) ? variable :
                    (name.charAt && (name.charAt(0) === '@'));
            };

            function evalName(context, name) {
                var value = "",
                    i, n = name.length,
                    output = { add: function(s) { value += s; } };
                for (i = 0; i < n; i++) {
                    name[i].eval(context).genCSS(context, output);
                }
                return value;
            }

            Rule.prototype = new Node();
            Rule.prototype.type = "Rule";
            Rule.prototype.genCSS = function(context, output) {
                output.add(this.name + (context.compress ? ':' : ': '), this.currentFileInfo, this.index);
                try {
                    this.value.genCSS(context, output);
                } catch (e) {
                    e.index = this.index;
                    e.filename = this.currentFileInfo.filename;
                    throw e;
                }
                output.add(this.important + ((this.inline || (context.lastRule && context.compress)) ? "" : ";"), this.currentFileInfo, this.index);
            };
            Rule.prototype.eval = function(context) {
                var strictMathBypass = false,
                    name = this.name,
                    evaldValue, variable = this.variable;
                if (typeof name !== "string") {
                    // expand 'primitive' name directly to get
                    // things faster (~10% for benchmark.less):
                    name = (name.length === 1) && (name[0] instanceof Keyword) ?
                        name[0].value : evalName(context, name);
                    variable = false; // never treat expanded interpolation as new variable name
                }
                if (name === "font" && !context.strictMath) {
                    strictMathBypass = true;
                    context.strictMath = true;
                }
                try {
                    context.importantScope.push({});
                    evaldValue = this.value.eval(context);

                    if (!this.variable && evaldValue.type === "DetachedRuleset") {
                        throw {
                            message: "Rulesets cannot be evaluated on a property.",
                            index: this.index,
                            filename: this.currentFileInfo.filename
                        };
                    }
                    var important = this.important,
                        importantResult = context.importantScope.pop();
                    if (!important && importantResult.important) {
                        important = importantResult.important;
                    }

                    return new Rule(name,
                        evaldValue,
                        important,
                        this.merge,
                        this.index, this.currentFileInfo, this.inline,
                        variable);
                } catch (e) {
                    if (typeof e.index !== 'number') {
                        e.index = this.index;
                        e.filename = this.currentFileInfo.filename;
                    }
                    throw e;
                } finally {
                    if (strictMathBypass) {
                        context.strictMath = false;
                    }
                }
            };
            Rule.prototype.makeImportant = function() {
                return new Rule(this.name,
                    this.value,
                    "!important",
                    this.merge,
                    this.index, this.currentFileInfo, this.inline);
            };

            module.exports = Rule;

        }, { "./keyword": 63, "./node": 68, "./value": 79 }],
        73: [function(require, module, exports) {
            var Node = require("./node"),
                Variable = require("./variable");

            var RulesetCall = function(variable) {
                this.variable = variable;
            };
            RulesetCall.prototype = new Node();
            RulesetCall.prototype.type = "RulesetCall";
            RulesetCall.prototype.eval = function(context) {
                var detachedRuleset = new Variable(this.variable).eval(context);
                return detachedRuleset.callEval(context);
            };
            module.exports = RulesetCall;

        }, { "./node": 68, "./variable": 80 }],
        74: [function(require, module, exports) {
            var Node = require("./node"),
                Rule = require("./rule"),
                Selector = require("./selector"),
                Element = require("./element"),
                Paren = require("./paren"),
                contexts = require("../contexts"),
                globalFunctionRegistry = require("../functions/function-registry"),
                defaultFunc = require("../functions/default"),
                getDebugInfo = require("./debug-info");

            var Ruleset = function(selectors, rules, strictImports) {
                this.selectors = selectors;
                this.rules = rules;
                this._lookups = {};
                this.strictImports = strictImports;
            };
            Ruleset.prototype = new Node();
            Ruleset.prototype.type = "Ruleset";
            Ruleset.prototype.isRuleset = true;
            Ruleset.prototype.isRulesetLike = true;
            Ruleset.prototype.accept = function(visitor) {
                if (this.paths) {
                    visitor.visitArray(this.paths, true);
                } else if (this.selectors) {
                    this.selectors = visitor.visitArray(this.selectors);
                }
                if (this.rules && this.rules.length) {
                    this.rules = visitor.visitArray(this.rules);
                }
            };
            Ruleset.prototype.eval = function(context) {
                var thisSelectors = this.selectors,
                    selectors,
                    selCnt, selector, i, hasOnePassingSelector = false;

                if (thisSelectors && (selCnt = thisSelectors.length)) {
                    selectors = [];
                    defaultFunc.error({
                        type: "Syntax",
                        message: "it is currently only allowed in parametric mixin guards,"
                    });
                    for (i = 0; i < selCnt; i++) {
                        selector = thisSelectors[i].eval(context);
                        selectors.push(selector);
                        if (selector.evaldCondition) {
                            hasOnePassingSelector = true;
                        }
                    }
                    defaultFunc.reset();
                } else {
                    hasOnePassingSelector = true;
                }

                var rules = this.rules ? this.rules.slice(0) : null,
                    ruleset = new Ruleset(selectors, rules, this.strictImports),
                    rule, subRule;

                ruleset.originalRuleset = this;
                ruleset.root = this.root;
                ruleset.firstRoot = this.firstRoot;
                ruleset.allowImports = this.allowImports;

                if (this.debugInfo) {
                    ruleset.debugInfo = this.debugInfo;
                }

                if (!hasOnePassingSelector) {
                    rules.length = 0;
                }

                // inherit a function registry from the frames stack when possible;
                // otherwise from the global registry
                ruleset.functionRegistry = (function(frames) {
                    var i = 0,
                        n = frames.length,
                        found;
                    for (; i !== n; ++i) {
                        found = frames[i].functionRegistry;
                        if (found) { return found; }
                    }
                    return globalFunctionRegistry;
                }(context.frames)).inherit();

                // push the current ruleset to the frames stack
                var ctxFrames = context.frames;
                ctxFrames.unshift(ruleset);

                // currrent selectors
                var ctxSelectors = context.selectors;
                if (!ctxSelectors) {
                    context.selectors = ctxSelectors = [];
                }
                ctxSelectors.unshift(this.selectors);

                // Evaluate imports
                if (ruleset.root || ruleset.allowImports || !ruleset.strictImports) {
                    ruleset.evalImports(context);
                }

                // Store the frames around mixin definitions,
                // so they can be evaluated like closures when the time comes.
                var rsRules = ruleset.rules,
                    rsRuleCnt = rsRules ? rsRules.length : 0;
                for (i = 0; i < rsRuleCnt; i++) {
                    if (rsRules[i].evalFirst) {
                        rsRules[i] = rsRules[i].eval(context);
                    }
                }

                var mediaBlockCount = (context.mediaBlocks && context.mediaBlocks.length) || 0;

                // Evaluate mixin calls.
                for (i = 0; i < rsRuleCnt; i++) {
                    if (rsRules[i].type === "MixinCall") {
                        /*jshint loopfunc:true */
                        rules = rsRules[i].eval(context).filter(function(r) {
                            if ((r instanceof Rule) && r.variable) {
                                // do not pollute the scope if the variable is
                                // already there. consider returning false here
                                // but we need a way to "return" variable from mixins
                                return !(ruleset.variable(r.name));
                            }
                            return true;
                        });
                        rsRules.splice.apply(rsRules, [i, 1].concat(rules));
                        rsRuleCnt += rules.length - 1;
                        i += rules.length - 1;
                        ruleset.resetCache();
                    } else if (rsRules[i].type === "RulesetCall") {
                        /*jshint loopfunc:true */
                        rules = rsRules[i].eval(context).rules.filter(function(r) {
                            if ((r instanceof Rule) && r.variable) {
                                // do not pollute the scope at all
                                return false;
                            }
                            return true;
                        });
                        rsRules.splice.apply(rsRules, [i, 1].concat(rules));
                        rsRuleCnt += rules.length - 1;
                        i += rules.length - 1;
                        ruleset.resetCache();
                    }
                }

                // Evaluate everything else
                for (i = 0; i < rsRules.length; i++) {
                    rule = rsRules[i];
                    if (!rule.evalFirst) {
                        rsRules[i] = rule = rule.eval ? rule.eval(context) : rule;
                    }
                }

                // Evaluate everything else
                for (i = 0; i < rsRules.length; i++) {
                    rule = rsRules[i];
                    // for rulesets, check if it is a css guard and can be removed
                    if (rule instanceof Ruleset && rule.selectors && rule.selectors.length === 1) {
                        // check if it can be folded in (e.g. & where)
                        if (rule.selectors[0].isJustParentSelector()) {
                            rsRules.splice(i--, 1);

                            for (var j = 0; j < rule.rules.length; j++) {
                                subRule = rule.rules[j];
                                if (!(subRule instanceof Rule) || !subRule.variable) {
                                    rsRules.splice(++i, 0, subRule);
                                }
                            }
                        }
                    }
                }

                // Pop the stack
                ctxFrames.shift();
                ctxSelectors.shift();

                if (context.mediaBlocks) {
                    for (i = mediaBlockCount; i < context.mediaBlocks.length; i++) {
                        context.mediaBlocks[i].bubbleSelectors(selectors);
                    }
                }

                return ruleset;
            };
            Ruleset.prototype.evalImports = function(context) {
                var rules = this.rules,
                    i, importRules;
                if (!rules) { return; }

                for (i = 0; i < rules.length; i++) {
                    if (rules[i].type === "Import") {
                        importRules = rules[i].eval(context);
                        if (importRules && importRules.length) {
                            rules.splice.apply(rules, [i, 1].concat(importRules));
                            i += importRules.length - 1;
                        } else {
                            rules.splice(i, 1, importRules);
                        }
                        this.resetCache();
                    }
                }
            };
            Ruleset.prototype.makeImportant = function() {
                var result = new Ruleset(this.selectors, this.rules.map(function(r) {
                    if (r.makeImportant) {
                        return r.makeImportant();
                    } else {
                        return r;
                    }
                }), this.strictImports);

                return result;
            };
            Ruleset.prototype.matchArgs = function(args) {
                return !args || args.length === 0;
            };
            // lets you call a css selector with a guard
            Ruleset.prototype.matchCondition = function(args, context) {
                var lastSelector = this.selectors[this.selectors.length - 1];
                if (!lastSelector.evaldCondition) {
                    return false;
                }
                if (lastSelector.condition &&
                    !lastSelector.condition.eval(
                        new contexts.Eval(context,
                            context.frames))) {
                    return false;
                }
                return true;
            };
            Ruleset.prototype.resetCache = function() {
                this._rulesets = null;
                this._variables = null;
                this._lookups = {};
            };
            Ruleset.prototype.variables = function() {
                if (!this._variables) {
                    this._variables = !this.rules ? {} : this.rules.reduce(function(hash, r) {
                        if (r instanceof Rule && r.variable === true) {
                            hash[r.name] = r;
                        }
                        // when evaluating variables in an import statement, imports have not been eval'd
                        // so we need to go inside import statements.
                        // guard against root being a string (in the case of inlined less)
                        if (r.type === "Import" && r.root && r.root.variables) {
                            var vars = r.root.variables();
                            for (var name in vars) {
                                if (vars.hasOwnProperty(name)) {
                                    hash[name] = vars[name];
                                }
                            }
                        }
                        return hash;
                    }, {});
                }
                return this._variables;
            };
            Ruleset.prototype.variable = function(name) {
                return this.variables()[name];
            };
            Ruleset.prototype.rulesets = function() {
                if (!this.rules) { return []; }

                var filtRules = [],
                    rules = this.rules,
                    cnt = rules.length,
                    i, rule;

                for (i = 0; i < cnt; i++) {
                    rule = rules[i];
                    if (rule.isRuleset) {
                        filtRules.push(rule);
                    }
                }

                return filtRules;
            };
            Ruleset.prototype.prependRule = function(rule) {
                var rules = this.rules;
                if (rules) {
                    rules.unshift(rule);
                } else {
                    this.rules = [rule];
                }
            };
            Ruleset.prototype.find = function(selector, self, filter) {
                self = self || this;
                var rules = [],
                    match, foundMixins,
                    key = selector.toCSS();

                if (key in this._lookups) { return this._lookups[key]; }

                this.rulesets().forEach(function(rule) {
                    if (rule !== self) {
                        for (var j = 0; j < rule.selectors.length; j++) {
                            match = selector.match(rule.selectors[j]);
                            if (match) {
                                if (selector.elements.length > match) {
                                    if (!filter || filter(rule)) {
                                        foundMixins = rule.find(new Selector(selector.elements.slice(match)), self, filter);
                                        for (var i = 0; i < foundMixins.length; ++i) {
                                            foundMixins[i].path.push(rule);
                                        }
                                        Array.prototype.push.apply(rules, foundMixins);
                                    }
                                } else {
                                    rules.push({ rule: rule, path: [] });
                                }
                                break;
                            }
                        }
                    }
                });
                this._lookups[key] = rules;
                return rules;
            };
            Ruleset.prototype.genCSS = function(context, output) {
                var i, j,
                    charsetRuleNodes = [],
                    ruleNodes = [],
                    debugInfo, // Line number debugging
                    rule,
                    path;

                context.tabLevel = (context.tabLevel || 0);

                if (!this.root) {
                    context.tabLevel++;
                }

                var tabRuleStr = context.compress ? '' : Array(context.tabLevel + 1).join("  "),
                    tabSetStr = context.compress ? '' : Array(context.tabLevel).join("  "),
                    sep;

                function isRulesetLikeNode(rule) {
                    // if it has nested rules, then it should be treated like a ruleset
                    // medias and comments do not have nested rules, but should be treated like rulesets anyway
                    // some directives and anonymous nodes are ruleset like, others are not
                    if (typeof rule.isRulesetLike === "boolean") {
                        return rule.isRulesetLike;
                    } else if (typeof rule.isRulesetLike === "function") {
                        return rule.isRulesetLike();
                    }

                    //anything else is assumed to be a rule
                    return false;
                }

                var charsetNodeIndex = 0;
                var importNodeIndex = 0;
                for (i = 0; i < this.rules.length; i++) {
                    rule = this.rules[i];
                    if (rule.type === "Comment") {
                        if (importNodeIndex === i) {
                            importNodeIndex++;
                        }
                        ruleNodes.push(rule);
                    } else if (rule.isCharset && rule.isCharset()) {
                        ruleNodes.splice(charsetNodeIndex, 0, rule);
                        charsetNodeIndex++;
                        importNodeIndex++;
                    } else if (rule.type === "Import") {
                        ruleNodes.splice(importNodeIndex, 0, rule);
                        importNodeIndex++;
                    } else {
                        ruleNodes.push(rule);
                    }
                }
                ruleNodes = charsetRuleNodes.concat(ruleNodes);

                // If this is the root node, we don't render
                // a selector, or {}.
                if (!this.root) {
                    debugInfo = getDebugInfo(context, this, tabSetStr);

                    if (debugInfo) {
                        output.add(debugInfo);
                        output.add(tabSetStr);
                    }

                    var paths = this.paths,
                        pathCnt = paths.length,
                        pathSubCnt;

                    sep = context.compress ? ',' : (',\n' + tabSetStr);

                    for (i = 0; i < pathCnt; i++) {
                        path = paths[i];
                        if (!(pathSubCnt = path.length)) { continue; }
                        if (i > 0) { output.add(sep); }

                        context.firstSelector = true;
                        path[0].genCSS(context, output);

                        context.firstSelector = false;
                        for (j = 1; j < pathSubCnt; j++) {
                            path[j].genCSS(context, output);
                        }
                    }

                    output.add((context.compress ? '{' : ' {\n') + tabRuleStr);
                }

                // Compile rules and rulesets
                for (i = 0; i < ruleNodes.length; i++) {
                    rule = ruleNodes[i];

                    if (i + 1 === ruleNodes.length) {
                        context.lastRule = true;
                    }

                    var currentLastRule = context.lastRule;
                    if (isRulesetLikeNode(rule)) {
                        context.lastRule = false;
                    }

                    if (rule.genCSS) {
                        rule.genCSS(context, output);
                    } else if (rule.value) {
                        output.add(rule.value.toString());
                    }

                    context.lastRule = currentLastRule;

                    if (!context.lastRule) {
                        output.add(context.compress ? '' : ('\n' + tabRuleStr));
                    } else {
                        context.lastRule = false;
                    }
                }

                if (!this.root) {
                    output.add((context.compress ? '}' : '\n' + tabSetStr + '}'));
                    context.tabLevel--;
                }

                if (!output.isEmpty() && !context.compress && this.firstRoot) {
                    output.add('\n');
                }
            };
            Ruleset.prototype.markReferenced = function() {
                var s;
                if (this.selectors) {
                    for (s = 0; s < this.selectors.length; s++) {
                        this.selectors[s].markReferenced();
                    }
                }

                if (this.rules) {
                    for (s = 0; s < this.rules.length; s++) {
                        if (this.rules[s].markReferenced) {
                            this.rules[s].markReferenced();
                        }
                    }
                }
            };
            Ruleset.prototype.getIsReferenced = function() {
                var i, j, path, selector;

                if (this.paths) {
                    for (i = 0; i < this.paths.length; i++) {
                        path = this.paths[i];
                        for (j = 0; j < path.length; j++) {
                            if (path[j].getIsReferenced && path[j].getIsReferenced()) {
                                return true;
                            }
                        }
                    }
                }

                if (this.selectors) {
                    for (i = 0; i < this.selectors.length; i++) {
                        selector = this.selectors[i];
                        if (selector.getIsReferenced && selector.getIsReferenced()) {
                            return true;
                        }
                    }
                }
                return false;
            };

            Ruleset.prototype.joinSelectors = function(paths, context, selectors) {
                for (var s = 0; s < selectors.length; s++) {
                    this.joinSelector(paths, context, selectors[s]);
                }
            };

            Ruleset.prototype.joinSelector = function(paths, context, selector) {

                function createParenthesis(elementsToPak, originalElement) {
                    var replacementParen, j;
                    if (elementsToPak.length === 0) {
                        replacementParen = new Paren(elementsToPak[0]);
                    } else {
                        var insideParent = [];
                        for (j = 0; j < elementsToPak.length; j++) {
                            insideParent.push(new Element(null, elementsToPak[j], originalElement.index, originalElement.currentFileInfo));
                        }
                        replacementParen = new Paren(new Selector(insideParent));
                    }
                    return replacementParen;
                }

                function createSelector(containedElement, originalElement) {
                    var element, selector;
                    element = new Element(null, containedElement, originalElement.index, originalElement.currentFileInfo);
                    selector = new Selector([element]);
                    return selector;
                }

                // replace all parent selectors inside `inSelector` by content of `context` array
                // resulting selectors are returned inside `paths` array
                // returns true if `inSelector` contained at least one parent selector
                function replaceParentSelector(paths, context, inSelector) {
                    // The paths are [[Selector]]
                    // The first list is a list of comma separated selectors
                    // The inner list is a list of inheritance separated selectors
                    // e.g.
                    // .a, .b {
                    //   .c {
                    //   }
                    // }
                    // == [[.a] [.c]] [[.b] [.c]]
                    //
                    var i, j, k, currentElements, newSelectors, selectorsMultiplied, sel, el, hadParentSelector = false,
                        length, lastSelector;

                    function findNestedSelector(element) {
                        var maybeSelector;
                        if (element.value.type !== 'Paren') {
                            return null;
                        }

                        maybeSelector = element.value.value;
                        if (maybeSelector.type !== 'Selector') {
                            return null;
                        }

                        return maybeSelector;
                    }

                    // the elements from the current selector so far
                    currentElements = [];
                    // the current list of new selectors to add to the path.
                    // We will build it up. We initiate it with one empty selector as we "multiply" the new selectors
                    // by the parents
                    newSelectors = [
                        []
                    ];

                    for (i = 0; i < inSelector.elements.length; i++) {
                        el = inSelector.elements[i];
                        // non parent reference elements just get added
                        if (el.value !== "&") {
                            var nestedSelector = findNestedSelector(el);
                            if (nestedSelector != null) {
                                // merge the current list of non parent selector elements
                                // on to the current list of selectors to add
                                mergeElementsOnToSelectors(currentElements, newSelectors);

                                var nestedPaths = [],
                                    replaced, replacedNewSelectors = [];
                                replaced = replaceParentSelector(nestedPaths, context, nestedSelector);
                                hadParentSelector = hadParentSelector || replaced;
                                //the nestedPaths array should have only one member - replaceParentSelector does not multiply selectors
                                for (k = 0; k < nestedPaths.length; k++) {
                                    var replacementSelector = createSelector(createParenthesis(nestedPaths[k], el), el);
                                    addAllReplacementsIntoPath(newSelectors, [replacementSelector], el, inSelector, replacedNewSelectors);
                                }
                                newSelectors = replacedNewSelectors;
                                currentElements = [];

                            } else {
                                currentElements.push(el);
                            }

                        } else {
                            hadParentSelector = true;
                            // the new list of selectors to add
                            selectorsMultiplied = [];

                            // merge the current list of non parent selector elements
                            // on to the current list of selectors to add
                            mergeElementsOnToSelectors(currentElements, newSelectors);

                            // loop through our current selectors
                            for (j = 0; j < newSelectors.length; j++) {
                                sel = newSelectors[j];
                                // if we don't have any parent paths, the & might be in a mixin so that it can be used
                                // whether there are parents or not
                                if (context.length === 0) {
                                    // the combinator used on el should now be applied to the next element instead so that
                                    // it is not lost
                                    if (sel.length > 0) {
                                        sel[0].elements.push(new Element(el.combinator, '', el.index, el.currentFileInfo));
                                    }
                                    selectorsMultiplied.push(sel);
                                } else {
                                    // and the parent selectors
                                    for (k = 0; k < context.length; k++) {
                                        // We need to put the current selectors
                                        // then join the last selector's elements on to the parents selectors
                                        var newSelectorPath = addReplacementIntoPath(sel, context[k], el, inSelector);
                                        // add that to our new set of selectors
                                        selectorsMultiplied.push(newSelectorPath);
                                    }
                                }
                            }

                            // our new selectors has been multiplied, so reset the state
                            newSelectors = selectorsMultiplied;
                            currentElements = [];
                        }
                    }

                    // if we have any elements left over (e.g. .a& .b == .b)
                    // add them on to all the current selectors
                    mergeElementsOnToSelectors(currentElements, newSelectors);

                    for (i = 0; i < newSelectors.length; i++) {
                        length = newSelectors[i].length;
                        if (length > 0) {
                            paths.push(newSelectors[i]);
                            lastSelector = newSelectors[i][length - 1];
                            newSelectors[i][length - 1] = lastSelector.createDerived(lastSelector.elements, inSelector.extendList);
                        }
                    }

                    return hadParentSelector;
                }

                // joins selector path from `beginningPath` with selector path in `addPath`
                // `replacedElement` contains element that is being replaced by `addPath`
                // returns concatenated path
                function addReplacementIntoPath(beginningPath, addPath, replacedElement, originalSelector) {
                    var newSelectorPath, lastSelector, newJoinedSelector;
                    // our new selector path
                    newSelectorPath = [];

                    //construct the joined selector - if & is the first thing this will be empty,
                    // if not newJoinedSelector will be the last set of elements in the selector
                    if (beginningPath.length > 0) {
                        newSelectorPath = beginningPath.slice(0);
                        lastSelector = newSelectorPath.pop();
                        newJoinedSelector = originalSelector.createDerived(lastSelector.elements.slice(0));
                    } else {
                        newJoinedSelector = originalSelector.createDerived([]);
                    }

                    if (addPath.length > 0) {
                        // /deep/ is a combinator that is valid without anything in front of it
                        // so if the & does not have a combinator that is "" or " " then
                        // and there is a combinator on the parent, then grab that.
                        // this also allows + a { & .b { .a & { ... though not sure why you would want to do that
                        var combinator = replacedElement.combinator,
                            parentEl = addPath[0].elements[0];
                        if (combinator.emptyOrWhitespace && !parentEl.combinator.emptyOrWhitespace) {
                            combinator = parentEl.combinator;
                        }
                        // join the elements so far with the first part of the parent
                        newJoinedSelector.elements.push(new Element(combinator, parentEl.value, replacedElement.index, replacedElement.currentFileInfo));
                        newJoinedSelector.elements = newJoinedSelector.elements.concat(addPath[0].elements.slice(1));
                    }

                    // now add the joined selector - but only if it is not empty
                    if (newJoinedSelector.elements.length !== 0) {
                        newSelectorPath.push(newJoinedSelector);
                    }

                    //put together the parent selectors after the join (e.g. the rest of the parent)
                    if (addPath.length > 1) {
                        newSelectorPath = newSelectorPath.concat(addPath.slice(1));
                    }
                    return newSelectorPath;
                }

                // joins selector path from `beginningPath` with every selector path in `addPaths` array
                // `replacedElement` contains element that is being replaced by `addPath`
                // returns array with all concatenated paths
                function addAllReplacementsIntoPath(beginningPath, addPaths, replacedElement, originalSelector, result) {
                    var j;
                    for (j = 0; j < beginningPath.length; j++) {
                        var newSelectorPath = addReplacementIntoPath(beginningPath[j], addPaths, replacedElement, originalSelector);
                        result.push(newSelectorPath);
                    }
                    return result;
                }

                function mergeElementsOnToSelectors(elements, selectors) {
                    var i, sel;

                    if (elements.length === 0) {
                        return;
                    }
                    if (selectors.length === 0) {
                        selectors.push([new Selector(elements)]);
                        return;
                    }

                    for (i = 0; i < selectors.length; i++) {
                        sel = selectors[i];

                        // if the previous thing in sel is a parent this needs to join on to it
                        if (sel.length > 0) {
                            sel[sel.length - 1] = sel[sel.length - 1].createDerived(sel[sel.length - 1].elements.concat(elements));
                        } else {
                            sel.push(new Selector(elements));
                        }
                    }
                }

                // joinSelector code follows
                var i, newPaths, hadParentSelector;

                newPaths = [];
                hadParentSelector = replaceParentSelector(newPaths, context, selector);

                if (!hadParentSelector) {
                    if (context.length > 0) {
                        newPaths = [];
                        for (i = 0; i < context.length; i++) {
                            newPaths.push(context[i].concat(selector));
                        }
                    } else {
                        newPaths = [
                            [selector]
                        ];
                    }
                }

                for (i = 0; i < newPaths.length; i++) {
                    paths.push(newPaths[i]);
                }

            };
            module.exports = Ruleset;

        }, { "../contexts": 10, "../functions/default": 19, "../functions/function-registry": 21, "./debug-info": 52, "./element": 56, "./node": 68, "./paren": 70, "./rule": 72, "./selector": 75 }],
        75: [function(require, module, exports) {
            var Node = require("./node"),
                Element = require("./element");

            var Selector = function(elements, extendList, condition, index, currentFileInfo, isReferenced) {
                this.elements = elements;
                this.extendList = extendList;
                this.condition = condition;
                this.currentFileInfo = currentFileInfo || {};
                this.isReferenced = isReferenced;
                if (!condition) {
                    this.evaldCondition = true;
                }
            };
            Selector.prototype = new Node();
            Selector.prototype.type = "Selector";
            Selector.prototype.accept = function(visitor) {
                if (this.elements) {
                    this.elements = visitor.visitArray(this.elements);
                }
                if (this.extendList) {
                    this.extendList = visitor.visitArray(this.extendList);
                }
                if (this.condition) {
                    this.condition = visitor.visit(this.condition);
                }
            };
            Selector.prototype.createDerived = function(elements, extendList, evaldCondition) {
                evaldCondition = (evaldCondition != null) ? evaldCondition : this.evaldCondition;
                var newSelector = new Selector(elements, extendList || this.extendList, null, this.index, this.currentFileInfo, this.isReferenced);
                newSelector.evaldCondition = evaldCondition;
                newSelector.mediaEmpty = this.mediaEmpty;
                return newSelector;
            };
            Selector.prototype.createEmptySelectors = function() {
                var el = new Element('', '&', this.index, this.currentFileInfo),
                    sels = [new Selector([el], null, null, this.index, this.currentFileInfo)];
                sels[0].mediaEmpty = true;
                return sels;
            };
            Selector.prototype.match = function(other) {
                var elements = this.elements,
                    len = elements.length,
                    olen, i;

                other.CacheElements();

                olen = other._elements.length;
                if (olen === 0 || len < olen) {
                    return 0;
                } else {
                    for (i = 0; i < olen; i++) {
                        if (elements[i].value !== other._elements[i]) {
                            return 0;
                        }
                    }
                }

                return olen; // return number of matched elements
            };
            Selector.prototype.CacheElements = function() {
                if (this._elements) {
                    return;
                }

                var elements = this.elements.map(function(v) {
                    return v.combinator.value + (v.value.value || v.value);
                }).join("").match(/[,&#\*\.\w-]([\w-]|(\\.))*/g);

                if (elements) {
                    if (elements[0] === "&") {
                        elements.shift();
                    }
                } else {
                    elements = [];
                }

                this._elements = elements;
            };
            Selector.prototype.isJustParentSelector = function() {
                return !this.mediaEmpty &&
                    this.elements.length === 1 &&
                    this.elements[0].value === '&' &&
                    (this.elements[0].combinator.value === ' ' || this.elements[0].combinator.value === '');
            };
            Selector.prototype.eval = function(context) {
                var evaldCondition = this.condition && this.condition.eval(context),
                    elements = this.elements,
                    extendList = this.extendList;

                elements = elements && elements.map(function(e) { return e.eval(context); });
                extendList = extendList && extendList.map(function(extend) { return extend.eval(context); });

                return this.createDerived(elements, extendList, evaldCondition);
            };
            Selector.prototype.genCSS = function(context, output) {
                var i, element;
                if ((!context || !context.firstSelector) && this.elements[0].combinator.value === "") {
                    output.add(' ', this.currentFileInfo, this.index);
                }
                if (!this._css) {
                    //TODO caching? speed comparison?
                    for (i = 0; i < this.elements.length; i++) {
                        element = this.elements[i];
                        element.genCSS(context, output);
                    }
                }
            };
            Selector.prototype.markReferenced = function() {
                this.isReferenced = true;
            };
            Selector.prototype.getIsReferenced = function() {
                return !this.currentFileInfo.reference || this.isReferenced;
            };
            Selector.prototype.getIsOutput = function() {
                return this.evaldCondition;
            };
            module.exports = Selector;

        }, { "./element": 56, "./node": 68 }],
        76: [function(require, module, exports) {
            var Node = require("./node");

            var UnicodeDescriptor = function(value) {
                this.value = value;
            };
            UnicodeDescriptor.prototype = new Node();
            UnicodeDescriptor.prototype.type = "UnicodeDescriptor";

            module.exports = UnicodeDescriptor;

        }, { "./node": 68 }],
        77: [function(require, module, exports) {
            var Node = require("./node"),
                unitConversions = require("../data/unit-conversions");

            var Unit = function(numerator, denominator, backupUnit) {
                this.numerator = numerator ? numerator.slice(0).sort() : [];
                this.denominator = denominator ? denominator.slice(0).sort() : [];
                if (backupUnit) {
                    this.backupUnit = backupUnit;
                } else if (numerator && numerator.length) {
                    this.backupUnit = numerator[0];
                }
            };

            Unit.prototype = new Node();
            Unit.prototype.type = "Unit";
            Unit.prototype.clone = function() {
                return new Unit(this.numerator.slice(0), this.denominator.slice(0), this.backupUnit);
            };
            Unit.prototype.genCSS = function(context, output) {
                // Dimension checks the unit is singular and throws an error if in strict math mode.
                var strictUnits = context && context.strictUnits;
                if (this.numerator.length === 1) {
                    output.add(this.numerator[0]); // the ideal situation
                } else if (!strictUnits && this.backupUnit) {
                    output.add(this.backupUnit);
                } else if (!strictUnits && this.denominator.length) {
                    output.add(this.denominator[0]);
                }
            };
            Unit.prototype.toString = function() {
                var i, returnStr = this.numerator.join("*");
                for (i = 0; i < this.denominator.length; i++) {
                    returnStr += "/" + this.denominator[i];
                }
                return returnStr;
            };
            Unit.prototype.compare = function(other) {
                return this.is(other.toString()) ? 0 : undefined;
            };
            Unit.prototype.is = function(unitString) {
                return this.toString().toUpperCase() === unitString.toUpperCase();
            };
            Unit.prototype.isLength = function() {
                return Boolean(this.toCSS().match(/px|em|%|in|cm|mm|pc|pt|ex/));
            };
            Unit.prototype.isEmpty = function() {
                return this.numerator.length === 0 && this.denominator.length === 0;
            };
            Unit.prototype.isSingular = function() {
                return this.numerator.length <= 1 && this.denominator.length === 0;
            };
            Unit.prototype.map = function(callback) {
                var i;

                for (i = 0; i < this.numerator.length; i++) {
                    this.numerator[i] = callback(this.numerator[i], false);
                }

                for (i = 0; i < this.denominator.length; i++) {
                    this.denominator[i] = callback(this.denominator[i], true);
                }
            };
            Unit.prototype.usedUnits = function() {
                var group, result = {},
                    mapUnit;

                mapUnit = function(atomicUnit) {
                    /*jshint loopfunc:true */
                    if (group.hasOwnProperty(atomicUnit) && !result[groupName]) {
                        result[groupName] = atomicUnit;
                    }

                    return atomicUnit;
                };

                for (var groupName in unitConversions) {
                    if (unitConversions.hasOwnProperty(groupName)) {
                        group = unitConversions[groupName];

                        this.map(mapUnit);
                    }
                }

                return result;
            };
            Unit.prototype.cancel = function() {
                var counter = {},
                    atomicUnit, i;

                for (i = 0; i < this.numerator.length; i++) {
                    atomicUnit = this.numerator[i];
                    counter[atomicUnit] = (counter[atomicUnit] || 0) + 1;
                }

                for (i = 0; i < this.denominator.length; i++) {
                    atomicUnit = this.denominator[i];
                    counter[atomicUnit] = (counter[atomicUnit] || 0) - 1;
                }

                this.numerator = [];
                this.denominator = [];

                for (atomicUnit in counter) {
                    if (counter.hasOwnProperty(atomicUnit)) {
                        var count = counter[atomicUnit];

                        if (count > 0) {
                            for (i = 0; i < count; i++) {
                                this.numerator.push(atomicUnit);
                            }
                        } else if (count < 0) {
                            for (i = 0; i < -count; i++) {
                                this.denominator.push(atomicUnit);
                            }
                        }
                    }
                }

                this.numerator.sort();
                this.denominator.sort();
            };
            module.exports = Unit;

        }, { "../data/unit-conversions": 13, "./node": 68 }],
        78: [function(require, module, exports) {
            var Node = require("./node");

            var URL = function(val, index, currentFileInfo, isEvald) {
                this.value = val;
                this.currentFileInfo = currentFileInfo;
                this.index = index;
                this.isEvald = isEvald;
            };
            URL.prototype = new Node();
            URL.prototype.type = "Url";
            URL.prototype.accept = function(visitor) {
                this.value = visitor.visit(this.value);
            };
            URL.prototype.genCSS = function(context, output) {
                output.add("url(");
                this.value.genCSS(context, output);
                output.add(")");
            };
            URL.prototype.eval = function(context) {
                var val = this.value.eval(context),
                    rootpath;

                if (!this.isEvald) {
                    // Add the base path if the URL is relative
                    rootpath = this.currentFileInfo && this.currentFileInfo.rootpath;
                    if (rootpath &&
                        typeof val.value === "string" &&
                        context.isPathRelative(val.value)) {

                        if (!val.quote) {
                            rootpath = rootpath.replace(/[\(\)'"\s]/g, function(match) { return "\\" + match; });
                        }
                        val.value = rootpath + val.value;
                    }

                    val.value = context.normalizePath(val.value);

                    // Add url args if enabled
                    if (context.urlArgs) {
                        if (!val.value.match(/^\s*data:/)) {
                            var delimiter = val.value.indexOf('?') === -1 ? '?' : '&';
                            var urlArgs = delimiter + context.urlArgs;
                            if (val.value.indexOf('#') !== -1) {
                                val.value = val.value.replace('#', urlArgs + '#');
                            } else {
                                val.value += urlArgs;
                            }
                        }
                    }
                }

                return new URL(val, this.index, this.currentFileInfo, true);
            };
            module.exports = URL;

        }, { "./node": 68 }],
        79: [function(require, module, exports) {
            var Node = require("./node");

            var Value = function(value) {
                this.value = value;
                if (!value) {
                    throw new Error("Value requires an array argument");
                }
            };
            Value.prototype = new Node();
            Value.prototype.type = "Value";
            Value.prototype.accept = function(visitor) {
                if (this.value) {
                    this.value = visitor.visitArray(this.value);
                }
            };
            Value.prototype.eval = function(context) {
                if (this.value.length === 1) {
                    return this.value[0].eval(context);
                } else {
                    return new Value(this.value.map(function(v) {
                        return v.eval(context);
                    }));
                }
            };
            Value.prototype.genCSS = function(context, output) {
                var i;
                for (i = 0; i < this.value.length; i++) {
                    this.value[i].genCSS(context, output);
                    if (i + 1 < this.value.length) {
                        output.add((context && context.compress) ? ',' : ', ');
                    }
                }
            };
            module.exports = Value;

        }, { "./node": 68 }],
        80: [function(require, module, exports) {
            var Node = require("./node");

            var Variable = function(name, index, currentFileInfo) {
                this.name = name;
                this.index = index;
                this.currentFileInfo = currentFileInfo || {};
            };
            Variable.prototype = new Node();
            Variable.prototype.type = "Variable";
            Variable.prototype.eval = function(context) {
                var variable, name = this.name;

                if (name.indexOf('@@') === 0) {
                    name = '@' + new Variable(name.slice(1), this.index, this.currentFileInfo).eval(context).value;
                }

                if (this.evaluating) {
                    throw {
                        type: 'Name',
                        message: "Recursive variable definition for " + name,
                        filename: this.currentFileInfo.filename,
                        index: this.index
                    };
                }

                this.evaluating = true;

                variable = this.find(context.frames, function(frame) {
                    var v = frame.variable(name);
                    if (v) {
                        if (v.important) {
                            var importantScope = context.importantScope[context.importantScope.length - 1];
                            importantScope.important = v.important;
                        }
                        return v.value.eval(context);
                    }
                });
                if (variable) {
                    this.evaluating = false;
                    return variable;
                } else {
                    throw {
                        type: 'Name',
                        message: "variable " + name + " is undefined",
                        filename: this.currentFileInfo.filename,
                        index: this.index
                    };
                }
            };
            Variable.prototype.find = function(obj, fun) {
                for (var i = 0, r; i < obj.length; i++) {
                    r = fun.call(obj, obj[i]);
                    if (r) { return r; }
                }
                return null;
            };
            module.exports = Variable;

        }, { "./node": 68 }],
        81: [function(require, module, exports) {
            module.exports = {
                getLocation: function(index, inputStream) {
                    var n = index + 1,
                        line = null,
                        column = -1;

                    while (--n >= 0 && inputStream.charAt(n) !== '\n') {
                        column++;
                    }

                    if (typeof index === 'number') {
                        line = (inputStream.slice(0, index).match(/\n/g) || "").length;
                    }

                    return {
                        line: line,
                        column: column
                    };
                }
            };

        }, {}],
        82: [function(require, module, exports) {
            var tree = require("../tree"),
                Visitor = require("./visitor"),
                logger = require("../logger");

            /*jshint loopfunc:true */

            var ExtendFinderVisitor = function() {
                this._visitor = new Visitor(this);
                this.contexts = [];
                this.allExtendsStack = [
                    []
                ];
            };

            ExtendFinderVisitor.prototype = {
                run: function(root) {
                    root = this._visitor.visit(root);
                    root.allExtends = this.allExtendsStack[0];
                    return root;
                },
                visitRule: function(ruleNode, visitArgs) {
                    visitArgs.visitDeeper = false;
                },
                visitMixinDefinition: function(mixinDefinitionNode, visitArgs) {
                    visitArgs.visitDeeper = false;
                },
                visitRuleset: function(rulesetNode, visitArgs) {
                    if (rulesetNode.root) {
                        return;
                    }

                    var i, j, extend, allSelectorsExtendList = [],
                        extendList;

                    // get &:extend(.a); rules which apply to all selectors in this ruleset
                    var rules = rulesetNode.rules,
                        ruleCnt = rules ? rules.length : 0;
                    for (i = 0; i < ruleCnt; i++) {
                        if (rulesetNode.rules[i] instanceof tree.Extend) {
                            allSelectorsExtendList.push(rules[i]);
                            rulesetNode.extendOnEveryPath = true;
                        }
                    }

                    // now find every selector and apply the extends that apply to all extends
                    // and the ones which apply to an individual extend
                    var paths = rulesetNode.paths;
                    for (i = 0; i < paths.length; i++) {
                        var selectorPath = paths[i],
                            selector = selectorPath[selectorPath.length - 1],
                            selExtendList = selector.extendList;

                        extendList = selExtendList ? selExtendList.slice(0).concat(allSelectorsExtendList) :
                            allSelectorsExtendList;

                        if (extendList) {
                            extendList = extendList.map(function(allSelectorsExtend) {
                                return allSelectorsExtend.clone();
                            });
                        }

                        for (j = 0; j < extendList.length; j++) {
                            this.foundExtends = true;
                            extend = extendList[j];
                            extend.findSelfSelectors(selectorPath);
                            extend.ruleset = rulesetNode;
                            if (j === 0) { extend.firstExtendOnThisSelectorPath = true; }
                            this.allExtendsStack[this.allExtendsStack.length - 1].push(extend);
                        }
                    }

                    this.contexts.push(rulesetNode.selectors);
                },
                visitRulesetOut: function(rulesetNode) {
                    if (!rulesetNode.root) {
                        this.contexts.length = this.contexts.length - 1;
                    }
                },
                visitMedia: function(mediaNode, visitArgs) {
                    mediaNode.allExtends = [];
                    this.allExtendsStack.push(mediaNode.allExtends);
                },
                visitMediaOut: function(mediaNode) {
                    this.allExtendsStack.length = this.allExtendsStack.length - 1;
                },
                visitDirective: function(directiveNode, visitArgs) {
                    directiveNode.allExtends = [];
                    this.allExtendsStack.push(directiveNode.allExtends);
                },
                visitDirectiveOut: function(directiveNode) {
                    this.allExtendsStack.length = this.allExtendsStack.length - 1;
                }
            };

            var ProcessExtendsVisitor = function() {
                this._visitor = new Visitor(this);
            };

            ProcessExtendsVisitor.prototype = {
                run: function(root) {
                    var extendFinder = new ExtendFinderVisitor();
                    this.extendIndicies = {};
                    extendFinder.run(root);
                    if (!extendFinder.foundExtends) { return root; }
                    root.allExtends = root.allExtends.concat(this.doExtendChaining(root.allExtends, root.allExtends));
                    this.allExtendsStack = [root.allExtends];
                    var newRoot = this._visitor.visit(root);
                    this.checkExtendsForNonMatched(root.allExtends);
                    return newRoot;
                },
                checkExtendsForNonMatched: function(extendList) {
                    var indicies = this.extendIndicies;
                    extendList.filter(function(extend) {
                        return !extend.hasFoundMatches && extend.parent_ids.length == 1;
                    }).forEach(function(extend) {
                        var selector = "_unknown_";
                        try {
                            selector = extend.selector.toCSS({});
                        } catch (_) {}

                        if (!indicies[extend.index + ' ' + selector]) {
                            indicies[extend.index + ' ' + selector] = true;
                            logger.warn("extend '" + selector + "' has no matches");
                        }
                    });
                },
                doExtendChaining: function(extendsList, extendsListTarget, iterationCount) {
                    //
                    // chaining is different from normal extension.. if we extend an extend then we are not just copying, altering
                    // and pasting the selector we would do normally, but we are also adding an extend with the same target selector
                    // this means this new extend can then go and alter other extends
                    //
                    // this method deals with all the chaining work - without it, extend is flat and doesn't work on other extend selectors
                    // this is also the most expensive.. and a match on one selector can cause an extension of a selector we had already
                    // processed if we look at each selector at a time, as is done in visitRuleset

                    var extendIndex, targetExtendIndex, matches, extendsToAdd = [],
                        newSelector, extendVisitor = this,
                        selectorPath,
                        extend, targetExtend, newExtend;

                    iterationCount = iterationCount || 0;

                    //loop through comparing every extend with every target extend.
                    // a target extend is the one on the ruleset we are looking at copy/edit/pasting in place
                    // e.g.  .a:extend(.b) {}  and .b:extend(.c) {} then the first extend extends the second one
                    // and the second is the target.
                    // the seperation into two lists allows us to process a subset of chains with a bigger set, as is the
                    // case when processing media queries
                    for (extendIndex = 0; extendIndex < extendsList.length; extendIndex++) {
                        for (targetExtendIndex = 0; targetExtendIndex < extendsListTarget.length; targetExtendIndex++) {

                            extend = extendsList[extendIndex];
                            targetExtend = extendsListTarget[targetExtendIndex];

                            // look for circular references
                            if (extend.parent_ids.indexOf(targetExtend.object_id) >= 0) { continue; }

                            // find a match in the target extends self selector (the bit before :extend)
                            selectorPath = [targetExtend.selfSelectors[0]];
                            matches = extendVisitor.findMatch(extend, selectorPath);

                            if (matches.length) {

                                extend.hasFoundMatches = true;

                                // we found a match, so for each self selector..
                                extend.selfSelectors.forEach(function(selfSelector) {

                                    // process the extend as usual
                                    newSelector = extendVisitor.extendSelector(matches, selectorPath, selfSelector);

                                    // but now we create a new extend from it
                                    newExtend = new(tree.Extend)(targetExtend.selector, targetExtend.option, 0);
                                    newExtend.selfSelectors = newSelector;

                                    // add the extend onto the list of extends for that selector
                                    newSelector[newSelector.length - 1].extendList = [newExtend];

                                    // record that we need to add it.
                                    extendsToAdd.push(newExtend);
                                    newExtend.ruleset = targetExtend.ruleset;

                                    //remember its parents for circular references
                                    newExtend.parent_ids = newExtend.parent_ids.concat(targetExtend.parent_ids, extend.parent_ids);

                                    // only process the selector once.. if we have :extend(.a,.b) then multiple
                                    // extends will look at the same selector path, so when extending
                                    // we know that any others will be duplicates in terms of what is added to the css
                                    if (targetExtend.firstExtendOnThisSelectorPath) {
                                        newExtend.firstExtendOnThisSelectorPath = true;
                                        targetExtend.ruleset.paths.push(newSelector);
                                    }
                                });
                            }
                        }
                    }

                    if (extendsToAdd.length) {
                        // try to detect circular references to stop a stack overflow.
                        // may no longer be needed.
                        this.extendChainCount++;
                        if (iterationCount > 100) {
                            var selectorOne = "{unable to calculate}";
                            var selectorTwo = "{unable to calculate}";
                            try {
                                selectorOne = extendsToAdd[0].selfSelectors[0].toCSS();
                                selectorTwo = extendsToAdd[0].selector.toCSS();
                            } catch (e) {}
                            throw {
                                message: "extend circular reference detected. One of the circular extends is currently:" +
                                    selectorOne + ":extend(" + selectorTwo + ")"
                            };
                        }

                        // now process the new extends on the existing rules so that we can handle a extending b extending c extending
                        // d extending e...
                        return extendsToAdd.concat(extendVisitor.doExtendChaining(extendsToAdd, extendsListTarget, iterationCount + 1));
                    } else {
                        return extendsToAdd;
                    }
                },
                visitRule: function(ruleNode, visitArgs) {
                    visitArgs.visitDeeper = false;
                },
                visitMixinDefinition: function(mixinDefinitionNode, visitArgs) {
                    visitArgs.visitDeeper = false;
                },
                visitSelector: function(selectorNode, visitArgs) {
                    visitArgs.visitDeeper = false;
                },
                visitRuleset: function(rulesetNode, visitArgs) {
                    if (rulesetNode.root) {
                        return;
                    }
                    var matches, pathIndex, extendIndex, allExtends = this.allExtendsStack[this.allExtendsStack.length - 1],
                        selectorsToAdd = [],
                        extendVisitor = this,
                        selectorPath;

                    // look at each selector path in the ruleset, find any extend matches and then copy, find and replace

                    for (extendIndex = 0; extendIndex < allExtends.length; extendIndex++) {
                        for (pathIndex = 0; pathIndex < rulesetNode.paths.length; pathIndex++) {
                            selectorPath = rulesetNode.paths[pathIndex];

                            // extending extends happens initially, before the main pass
                            if (rulesetNode.extendOnEveryPath) { continue; }
                            var extendList = selectorPath[selectorPath.length - 1].extendList;
                            if (extendList && extendList.length) { continue; }

                            matches = this.findMatch(allExtends[extendIndex], selectorPath);

                            if (matches.length) {
                                allExtends[extendIndex].hasFoundMatches = true;

                                allExtends[extendIndex].selfSelectors.forEach(function(selfSelector) {
                                    selectorsToAdd.push(extendVisitor.extendSelector(matches, selectorPath, selfSelector));
                                });
                            }
                        }
                    }
                    rulesetNode.paths = rulesetNode.paths.concat(selectorsToAdd);
                },
                findMatch: function(extend, haystackSelectorPath) {
                    //
                    // look through the haystack selector path to try and find the needle - extend.selector
                    // returns an array of selector matches that can then be replaced
                    //
                    var haystackSelectorIndex, hackstackSelector, hackstackElementIndex, haystackElement,
                        targetCombinator, i,
                        extendVisitor = this,
                        needleElements = extend.selector.elements,
                        potentialMatches = [],
                        potentialMatch, matches = [];

                    // loop through the haystack elements
                    for (haystackSelectorIndex = 0; haystackSelectorIndex < haystackSelectorPath.length; haystackSelectorIndex++) {
                        hackstackSelector = haystackSelectorPath[haystackSelectorIndex];

                        for (hackstackElementIndex = 0; hackstackElementIndex < hackstackSelector.elements.length; hackstackElementIndex++) {

                            haystackElement = hackstackSelector.elements[hackstackElementIndex];

                            // if we allow elements before our match we can add a potential match every time. otherwise only at the first element.
                            if (extend.allowBefore || (haystackSelectorIndex === 0 && hackstackElementIndex === 0)) {
                                potentialMatches.push({
                                    pathIndex: haystackSelectorIndex,
                                    index: hackstackElementIndex,
                                    matched: 0,
                                    initialCombinator: haystackElement.combinator
                                });
                            }

                            for (i = 0; i < potentialMatches.length; i++) {
                                potentialMatch = potentialMatches[i];

                                // selectors add " " onto the first element. When we use & it joins the selectors together, but if we don't
                                // then each selector in haystackSelectorPath has a space before it added in the toCSS phase. so we need to
                                // work out what the resulting combinator will be
                                targetCombinator = haystackElement.combinator.value;
                                if (targetCombinator === '' && hackstackElementIndex === 0) {
                                    targetCombinator = ' ';
                                }

                                // if we don't match, null our match to indicate failure
                                if (!extendVisitor.isElementValuesEqual(needleElements[potentialMatch.matched].value, haystackElement.value) ||
                                    (potentialMatch.matched > 0 && needleElements[potentialMatch.matched].combinator.value !== targetCombinator)) {
                                    potentialMatch = null;
                                } else {
                                    potentialMatch.matched++;
                                }

                                // if we are still valid and have finished, test whether we have elements after and whether these are allowed
                                if (potentialMatch) {
                                    potentialMatch.finished = potentialMatch.matched === needleElements.length;
                                    if (potentialMatch.finished &&
                                        (!extend.allowAfter &&
                                            (hackstackElementIndex + 1 < hackstackSelector.elements.length || haystackSelectorIndex + 1 < haystackSelectorPath.length))) {
                                        potentialMatch = null;
                                    }
                                }
                                // if null we remove, if not, we are still valid, so either push as a valid match or continue
                                if (potentialMatch) {
                                    if (potentialMatch.finished) {
                                        potentialMatch.length = needleElements.length;
                                        potentialMatch.endPathIndex = haystackSelectorIndex;
                                        potentialMatch.endPathElementIndex = hackstackElementIndex + 1; // index after end of match
                                        potentialMatches.length = 0; // we don't allow matches to overlap, so start matching again
                                        matches.push(potentialMatch);
                                    }
                                } else {
                                    potentialMatches.splice(i, 1);
                                    i--;
                                }
                            }
                        }
                    }
                    return matches;
                },
                isElementValuesEqual: function(elementValue1, elementValue2) {
                    if (typeof elementValue1 === "string" || typeof elementValue2 === "string") {
                        return elementValue1 === elementValue2;
                    }
                    if (elementValue1 instanceof tree.Attribute) {
                        if (elementValue1.op !== elementValue2.op || elementValue1.key !== elementValue2.key) {
                            return false;
                        }
                        if (!elementValue1.value || !elementValue2.value) {
                            if (elementValue1.value || elementValue2.value) {
                                return false;
                            }
                            return true;
                        }
                        elementValue1 = elementValue1.value.value || elementValue1.value;
                        elementValue2 = elementValue2.value.value || elementValue2.value;
                        return elementValue1 === elementValue2;
                    }
                    elementValue1 = elementValue1.value;
                    elementValue2 = elementValue2.value;
                    if (elementValue1 instanceof tree.Selector) {
                        if (!(elementValue2 instanceof tree.Selector) || elementValue1.elements.length !== elementValue2.elements.length) {
                            return false;
                        }
                        for (var i = 0; i < elementValue1.elements.length; i++) {
                            if (elementValue1.elements[i].combinator.value !== elementValue2.elements[i].combinator.value) {
                                if (i !== 0 || (elementValue1.elements[i].combinator.value || ' ') !== (elementValue2.elements[i].combinator.value || ' ')) {
                                    return false;
                                }
                            }
                            if (!this.isElementValuesEqual(elementValue1.elements[i].value, elementValue2.elements[i].value)) {
                                return false;
                            }
                        }
                        return true;
                    }
                    return false;
                },
                extendSelector: function(matches, selectorPath, replacementSelector) {

                    //for a set of matches, replace each match with the replacement selector

                    var currentSelectorPathIndex = 0,
                        currentSelectorPathElementIndex = 0,
                        path = [],
                        matchIndex,
                        selector,
                        firstElement,
                        match,
                        newElements;

                    for (matchIndex = 0; matchIndex < matches.length; matchIndex++) {
                        match = matches[matchIndex];
                        selector = selectorPath[match.pathIndex];
                        firstElement = new tree.Element(
                            match.initialCombinator,
                            replacementSelector.elements[0].value,
                            replacementSelector.elements[0].index,
                            replacementSelector.elements[0].currentFileInfo
                        );

                        if (match.pathIndex > currentSelectorPathIndex && currentSelectorPathElementIndex > 0) {
                            path[path.length - 1].elements = path[path.length - 1]
                                .elements.concat(selectorPath[currentSelectorPathIndex].elements.slice(currentSelectorPathElementIndex));
                            currentSelectorPathElementIndex = 0;
                            currentSelectorPathIndex++;
                        }

                        newElements = selector.elements
                            .slice(currentSelectorPathElementIndex, match.index)
                            .concat([firstElement])
                            .concat(replacementSelector.elements.slice(1));

                        if (currentSelectorPathIndex === match.pathIndex && matchIndex > 0) {
                            path[path.length - 1].elements =
                                path[path.length - 1].elements.concat(newElements);
                        } else {
                            path = path.concat(selectorPath.slice(currentSelectorPathIndex, match.pathIndex));

                            path.push(new tree.Selector(
                                newElements
                            ));
                        }
                        currentSelectorPathIndex = match.endPathIndex;
                        currentSelectorPathElementIndex = match.endPathElementIndex;
                        if (currentSelectorPathElementIndex >= selectorPath[currentSelectorPathIndex].elements.length) {
                            currentSelectorPathElementIndex = 0;
                            currentSelectorPathIndex++;
                        }
                    }

                    if (currentSelectorPathIndex < selectorPath.length && currentSelectorPathElementIndex > 0) {
                        path[path.length - 1].elements = path[path.length - 1]
                            .elements.concat(selectorPath[currentSelectorPathIndex].elements.slice(currentSelectorPathElementIndex));
                        currentSelectorPathIndex++;
                    }

                    path = path.concat(selectorPath.slice(currentSelectorPathIndex, selectorPath.length));

                    return path;
                },
                visitRulesetOut: function(rulesetNode) {},
                visitMedia: function(mediaNode, visitArgs) {
                    var newAllExtends = mediaNode.allExtends.concat(this.allExtendsStack[this.allExtendsStack.length - 1]);
                    newAllExtends = newAllExtends.concat(this.doExtendChaining(newAllExtends, mediaNode.allExtends));
                    this.allExtendsStack.push(newAllExtends);
                },
                visitMediaOut: function(mediaNode) {
                    var lastIndex = this.allExtendsStack.length - 1;
                    this.allExtendsStack.length = lastIndex;
                },
                visitDirective: function(directiveNode, visitArgs) {
                    var newAllExtends = directiveNode.allExtends.concat(this.allExtendsStack[this.allExtendsStack.length - 1]);
                    newAllExtends = newAllExtends.concat(this.doExtendChaining(newAllExtends, directiveNode.allExtends));
                    this.allExtendsStack.push(newAllExtends);
                },
                visitDirectiveOut: function(directiveNode) {
                    var lastIndex = this.allExtendsStack.length - 1;
                    this.allExtendsStack.length = lastIndex;
                }
            };

            module.exports = ProcessExtendsVisitor;

        }, { "../logger": 31, "../tree": 60, "./visitor": 88 }],
        83: [function(require, module, exports) {
            function ImportSequencer(onSequencerEmpty) {
                this.imports = [];
                this.variableImports = [];
                this._onSequencerEmpty = onSequencerEmpty;
                this._currentDepth = 0;
            }

            ImportSequencer.prototype.addImport = function(callback) {
                var importSequencer = this,
                    importItem = {
                        callback: callback,
                        args: null,
                        isReady: false
                    };
                this.imports.push(importItem);
                return function() {
                    importItem.args = Array.prototype.slice.call(arguments, 0);
                    importItem.isReady = true;
                    importSequencer.tryRun();
                };
            };

            ImportSequencer.prototype.addVariableImport = function(callback) {
                this.variableImports.push(callback);
            };

            ImportSequencer.prototype.tryRun = function() {
                this._currentDepth++;
                try {
                    while (true) {
                        while (this.imports.length > 0) {
                            var importItem = this.imports[0];
                            if (!importItem.isReady) {
                                return;
                            }
                            this.imports = this.imports.slice(1);
                            importItem.callback.apply(null, importItem.args);
                        }
                        if (this.variableImports.length === 0) {
                            break;
                        }
                        var variableImport = this.variableImports[0];
                        this.variableImports = this.variableImports.slice(1);
                        variableImport();
                    }
                } finally {
                    this._currentDepth--;
                }
                if (this._currentDepth === 0 && this._onSequencerEmpty) {
                    this._onSequencerEmpty();
                }
            };

            module.exports = ImportSequencer;

        }, {}],
        84: [function(require, module, exports) {
            var contexts = require("../contexts"),
                Visitor = require("./visitor"),
                ImportSequencer = require("./import-sequencer");

            var ImportVisitor = function(importer, finish) {

                this._visitor = new Visitor(this);
                this._importer = importer;
                this._finish = finish;
                this.context = new contexts.Eval();
                this.importCount = 0;
                this.onceFileDetectionMap = {};
                this.recursionDetector = {};
                this._sequencer = new ImportSequencer(this._onSequencerEmpty.bind(this));
            };

            ImportVisitor.prototype = {
                isReplacing: false,
                run: function(root) {
                    try {
                        // process the contents
                        this._visitor.visit(root);
                    } catch (e) {
                        this.error = e;
                    }

                    this.isFinished = true;
                    this._sequencer.tryRun();
                },
                _onSequencerEmpty: function() {
                    if (!this.isFinished) {
                        return;
                    }
                    this._finish(this.error);
                },
                visitImport: function(importNode, visitArgs) {
                    var inlineCSS = importNode.options.inline;

                    if (!importNode.css || inlineCSS) {

                        var context = new contexts.Eval(this.context, this.context.frames.slice(0));
                        var importParent = context.frames[0];

                        this.importCount++;
                        if (importNode.isVariableImport()) {
                            this._sequencer.addVariableImport(this.processImportNode.bind(this, importNode, context, importParent));
                        } else {
                            this.processImportNode(importNode, context, importParent);
                        }
                    }
                    visitArgs.visitDeeper = false;
                },
                processImportNode: function(importNode, context, importParent) {
                    var evaldImportNode,
                        inlineCSS = importNode.options.inline;

                    try {
                        evaldImportNode = importNode.evalForImport(context);
                    } catch (e) {
                        if (!e.filename) {
                            e.index = importNode.index;
                            e.filename = importNode.currentFileInfo.filename;
                        }
                        // attempt to eval properly and treat as css
                        importNode.css = true;
                        // if that fails, this error will be thrown
                        importNode.error = e;
                    }

                    if (evaldImportNode && (!evaldImportNode.css || inlineCSS)) {

                        if (evaldImportNode.options.multiple) {
                            context.importMultiple = true;
                        }

                        // try appending if we haven't determined if it is css or not
                        var tryAppendLessExtension = evaldImportNode.css === undefined;

                        for (var i = 0; i < importParent.rules.length; i++) {
                            if (importParent.rules[i] === importNode) {
                                importParent.rules[i] = evaldImportNode;
                                break;
                            }
                        }

                        var onImported = this.onImported.bind(this, evaldImportNode, context),
                            sequencedOnImported = this._sequencer.addImport(onImported);

                        this._importer.push(evaldImportNode.getPath(), tryAppendLessExtension, evaldImportNode.currentFileInfo,
                            evaldImportNode.options, sequencedOnImported);
                    } else {
                        this.importCount--;
                        if (this.isFinished) {
                            this._sequencer.tryRun();
                        }
                    }
                },
                onImported: function(importNode, context, e, root, importedAtRoot, fullPath) {
                    if (e) {
                        if (!e.filename) {
                            e.index = importNode.index;
                            e.filename = importNode.currentFileInfo.filename;
                        }
                        this.error = e;
                    }

                    var importVisitor = this,
                        inlineCSS = importNode.options.inline,
                        isPlugin = importNode.options.plugin,
                        duplicateImport = importedAtRoot || fullPath in importVisitor.recursionDetector;

                    if (!context.importMultiple) {
                        if (duplicateImport) {
                            importNode.skip = true;
                        } else {
                            importNode.skip = function() {
                                if (fullPath in importVisitor.onceFileDetectionMap) {
                                    return true;
                                }
                                importVisitor.onceFileDetectionMap[fullPath] = true;
                                return false;
                            };
                        }
                    }

                    if (root) {
                        importNode.root = root;
                        importNode.importedFilename = fullPath;

                        if (!inlineCSS && !isPlugin && (context.importMultiple || !duplicateImport)) {
                            importVisitor.recursionDetector[fullPath] = true;

                            var oldContext = this.context;
                            this.context = context;
                            try {
                                this._visitor.visit(root);
                            } catch (e) {
                                this.error = e;
                            }
                            this.context = oldContext;
                        }
                    }

                    importVisitor.importCount--;

                    if (importVisitor.isFinished) {
                        importVisitor._sequencer.tryRun();
                    }
                },
                visitRule: function(ruleNode, visitArgs) {
                    if (ruleNode.value.type === "DetachedRuleset") {
                        this.context.frames.unshift(ruleNode);
                    } else {
                        visitArgs.visitDeeper = false;
                    }
                },
                visitRuleOut: function(ruleNode) {
                    if (ruleNode.value.type === "DetachedRuleset") {
                        this.context.frames.shift();
                    }
                },
                visitDirective: function(directiveNode, visitArgs) {
                    this.context.frames.unshift(directiveNode);
                },
                visitDirectiveOut: function(directiveNode) {
                    this.context.frames.shift();
                },
                visitMixinDefinition: function(mixinDefinitionNode, visitArgs) {
                    this.context.frames.unshift(mixinDefinitionNode);
                },
                visitMixinDefinitionOut: function(mixinDefinitionNode) {
                    this.context.frames.shift();
                },
                visitRuleset: function(rulesetNode, visitArgs) {
                    this.context.frames.unshift(rulesetNode);
                },
                visitRulesetOut: function(rulesetNode) {
                    this.context.frames.shift();
                },
                visitMedia: function(mediaNode, visitArgs) {
                    this.context.frames.unshift(mediaNode.rules[0]);
                },
                visitMediaOut: function(mediaNode) {
                    this.context.frames.shift();
                }
            };
            module.exports = ImportVisitor;

        }, { "../contexts": 10, "./import-sequencer": 83, "./visitor": 88 }],
        85: [function(require, module, exports) {
            var visitors = {
                Visitor: require("./visitor"),
                ImportVisitor: require('./import-visitor'),
                ExtendVisitor: require('./extend-visitor'),
                JoinSelectorVisitor: require('./join-selector-visitor'),
                ToCSSVisitor: require('./to-css-visitor')
            };

            module.exports = visitors;

        }, { "./extend-visitor": 82, "./import-visitor": 84, "./join-selector-visitor": 86, "./to-css-visitor": 87, "./visitor": 88 }],
        86: [function(require, module, exports) {
            var Visitor = require("./visitor");

            var JoinSelectorVisitor = function() {
                this.contexts = [
                    []
                ];
                this._visitor = new Visitor(this);
            };

            JoinSelectorVisitor.prototype = {
                run: function(root) {
                    return this._visitor.visit(root);
                },
                visitRule: function(ruleNode, visitArgs) {
                    visitArgs.visitDeeper = false;
                },
                visitMixinDefinition: function(mixinDefinitionNode, visitArgs) {
                    visitArgs.visitDeeper = false;
                },

                visitRuleset: function(rulesetNode, visitArgs) {
                    var context = this.contexts[this.contexts.length - 1],
                        paths = [],
                        selectors;

                    this.contexts.push(paths);

                    if (!rulesetNode.root) {
                        selectors = rulesetNode.selectors;
                        if (selectors) {
                            selectors = selectors.filter(function(selector) { return selector.getIsOutput(); });
                            rulesetNode.selectors = selectors.length ? selectors : (selectors = null);
                            if (selectors) { rulesetNode.joinSelectors(paths, context, selectors); }
                        }
                        if (!selectors) { rulesetNode.rules = null; }
                        rulesetNode.paths = paths;
                    }
                },
                visitRulesetOut: function(rulesetNode) {
                    this.contexts.length = this.contexts.length - 1;
                },
                visitMedia: function(mediaNode, visitArgs) {
                    var context = this.contexts[this.contexts.length - 1];
                    mediaNode.rules[0].root = (context.length === 0 || context[0].multiMedia);
                },
                visitDirective: function(directiveNode, visitArgs) {
                    var context = this.contexts[this.contexts.length - 1];
                    if (directiveNode.rules && directiveNode.rules.length) {
                        directiveNode.rules[0].root = (directiveNode.isRooted || context.length === 0 || null);
                    }
                }
            };

            module.exports = JoinSelectorVisitor;

        }, { "./visitor": 88 }],
        87: [function(require, module, exports) {
            var tree = require("../tree"),
                Visitor = require("./visitor");

            var ToCSSVisitor = function(context) {
                this._visitor = new Visitor(this);
                this._context = context;
            };

            ToCSSVisitor.prototype = {
                isReplacing: true,
                run: function(root) {
                    return this._visitor.visit(root);
                },

                visitRule: function(ruleNode, visitArgs) {
                    if (ruleNode.variable) {
                        return;
                    }
                    return ruleNode;
                },

                visitMixinDefinition: function(mixinNode, visitArgs) {
                    // mixin definitions do not get eval'd - this means they keep state
                    // so we have to clear that state here so it isn't used if toCSS is called twice
                    mixinNode.frames = [];
                },

                visitExtend: function(extendNode, visitArgs) {},

                visitComment: function(commentNode, visitArgs) {
                    if (commentNode.isSilent(this._context)) {
                        return;
                    }
                    return commentNode;
                },

                visitMedia: function(mediaNode, visitArgs) {
                    mediaNode.accept(this._visitor);
                    visitArgs.visitDeeper = false;

                    if (!mediaNode.rules.length) {
                        return;
                    }
                    return mediaNode;
                },

                visitImport: function(importNode, visitArgs) {
                    if (importNode.path.currentFileInfo.reference !== undefined && importNode.css) {
                        return;
                    }
                    return importNode;
                },

                visitDirective: function(directiveNode, visitArgs) {
                    if (directiveNode.name === "@charset") {
                        if (!directiveNode.getIsReferenced()) {
                            return;
                        }
                        // Only output the debug info together with subsequent @charset definitions
                        // a comment (or @media statement) before the actual @charset directive would
                        // be considered illegal css as it has to be on the first line
                        if (this.charset) {
                            if (directiveNode.debugInfo) {
                                var comment = new tree.Comment("/* " + directiveNode.toCSS(this._context).replace(/\n/g, "") + " */\n");
                                comment.debugInfo = directiveNode.debugInfo;
                                return this._visitor.visit(comment);
                            }
                            return;
                        }
                        this.charset = true;
                    }

                    function hasVisibleChild(directiveNode) {
                        //prepare list of childs
                        var rule, bodyRules = directiveNode.rules;
                        //if there is only one nested ruleset and that one has no path, then it is
                        //just fake ruleset that got not replaced and we need to look inside it to
                        //get real childs
                        if (bodyRules.length === 1 && (!bodyRules[0].paths || bodyRules[0].paths.length === 0)) {
                            bodyRules = bodyRules[0].rules;
                        }
                        for (var r = 0; r < bodyRules.length; r++) {
                            rule = bodyRules[r];
                            if (rule.getIsReferenced && rule.getIsReferenced()) {
                                //the directive contains something that was referenced (likely by extend)
                                //therefore it needs to be shown in output too
                                return true;
                            }
                        }
                        return false;
                    }

                    if (directiveNode.rules && directiveNode.rules.length) {
                        //it is still true that it is only one ruleset in array
                        //this is last such moment
                        this._mergeRules(directiveNode.rules[0].rules);
                        //process childs
                        directiveNode.accept(this._visitor);
                        visitArgs.visitDeeper = false;

                        // the directive was directly referenced and therefore needs to be shown in the output
                        if (directiveNode.getIsReferenced()) {
                            return directiveNode;
                        }

                        if (!directiveNode.rules || !directiveNode.rules.length) {
                            return;
                        }

                        //the directive was not directly referenced - we need to check whether some of its childs
                        //was referenced
                        if (hasVisibleChild(directiveNode)) {
                            //marking as referenced in case the directive is stored inside another directive
                            directiveNode.markReferenced();
                            return directiveNode;
                        }

                        //The directive was not directly referenced and does not contain anything that
                        //was referenced. Therefore it must not be shown in output.
                        return;
                    } else {
                        if (!directiveNode.getIsReferenced()) {
                            return;
                        }
                    }
                    return directiveNode;
                },

                checkPropertiesInRoot: function(rules) {
                    var ruleNode;
                    for (var i = 0; i < rules.length; i++) {
                        ruleNode = rules[i];
                        if (ruleNode instanceof tree.Rule && !ruleNode.variable) {
                            throw {
                                message: "properties must be inside selector blocks, they cannot be in the root.",
                                index: ruleNode.index,
                                filename: ruleNode.currentFileInfo ? ruleNode.currentFileInfo.filename : null
                            };
                        }
                    }
                },

                visitRuleset: function(rulesetNode, visitArgs) {
                    var rule, rulesets = [];
                    if (rulesetNode.firstRoot) {
                        this.checkPropertiesInRoot(rulesetNode.rules);
                    }
                    if (!rulesetNode.root) {
                        if (rulesetNode.paths) {
                            rulesetNode.paths = rulesetNode.paths
                                .filter(function(p) {
                                    var i;
                                    if (p[0].elements[0].combinator.value === ' ') {
                                        p[0].elements[0].combinator = new(tree.Combinator)('');
                                    }
                                    for (i = 0; i < p.length; i++) {
                                        if (p[i].getIsReferenced() && p[i].getIsOutput()) {
                                            return true;
                                        }
                                    }
                                    return false;
                                });
                        }

                        // Compile rules and rulesets
                        var nodeRules = rulesetNode.rules,
                            nodeRuleCnt = nodeRules ? nodeRules.length : 0;
                        for (var i = 0; i < nodeRuleCnt;) {
                            rule = nodeRules[i];
                            if (rule && rule.rules) {
                                // visit because we are moving them out from being a child
                                rulesets.push(this._visitor.visit(rule));
                                nodeRules.splice(i, 1);
                                nodeRuleCnt--;
                                continue;
                            }
                            i++;
                        }
                        // accept the visitor to remove rules and refactor itself
                        // then we can decide now whether we want it or not
                        if (nodeRuleCnt > 0) {
                            rulesetNode.accept(this._visitor);
                        } else {
                            rulesetNode.rules = null;
                        }
                        visitArgs.visitDeeper = false;

                        nodeRules = rulesetNode.rules;
                        if (nodeRules) {
                            this._mergeRules(nodeRules);
                            nodeRules = rulesetNode.rules;
                        }
                        if (nodeRules) {
                            this._removeDuplicateRules(nodeRules);
                            nodeRules = rulesetNode.rules;
                        }

                        // now decide whether we keep the ruleset
                        if (nodeRules && nodeRules.length > 0 && rulesetNode.paths.length > 0) {
                            rulesets.splice(0, 0, rulesetNode);
                        }
                    } else {
                        rulesetNode.accept(this._visitor);
                        visitArgs.visitDeeper = false;
                        if (rulesetNode.firstRoot || (rulesetNode.rules && rulesetNode.rules.length > 0)) {
                            rulesets.splice(0, 0, rulesetNode);
                        }
                    }
                    if (rulesets.length === 1) {
                        return rulesets[0];
                    }
                    return rulesets;
                },

                _removeDuplicateRules: function(rules) {
                    if (!rules) { return; }

                    // remove duplicates
                    var ruleCache = {},
                        ruleList, rule, i;

                    for (i = rules.length - 1; i >= 0; i--) {
                        rule = rules[i];
                        if (rule instanceof tree.Rule) {
                            if (!ruleCache[rule.name]) {
                                ruleCache[rule.name] = rule;
                            } else {
                                ruleList = ruleCache[rule.name];
                                if (ruleList instanceof tree.Rule) {
                                    ruleList = ruleCache[rule.name] = [ruleCache[rule.name].toCSS(this._context)];
                                }
                                var ruleCSS = rule.toCSS(this._context);
                                if (ruleList.indexOf(ruleCSS) !== -1) {
                                    rules.splice(i, 1);
                                } else {
                                    ruleList.push(ruleCSS);
                                }
                            }
                        }
                    }
                },

                _mergeRules: function(rules) {
                    if (!rules) { return; }

                    var groups = {},
                        parts,
                        rule,
                        key;

                    for (var i = 0; i < rules.length; i++) {
                        rule = rules[i];

                        if ((rule instanceof tree.Rule) && rule.merge) {
                            key = [rule.name,
                                rule.important ? "!" : ""
                            ].join(",");

                            if (!groups[key]) {
                                groups[key] = [];
                            } else {
                                rules.splice(i--, 1);
                            }

                            groups[key].push(rule);
                        }
                    }

                    Object.keys(groups).map(function(k) {

                        function toExpression(values) {
                            return new(tree.Expression)(values.map(function(p) {
                                return p.value;
                            }));
                        }

                        function toValue(values) {
                            return new(tree.Value)(values.map(function(p) {
                                return p;
                            }));
                        }

                        parts = groups[k];

                        if (parts.length > 1) {
                            rule = parts[0];
                            var spacedGroups = [];
                            var lastSpacedGroup = [];
                            parts.map(function(p) {
                                if (p.merge === "+") {
                                    if (lastSpacedGroup.length > 0) {
                                        spacedGroups.push(toExpression(lastSpacedGroup));
                                    }
                                    lastSpacedGroup = [];
                                }
                                lastSpacedGroup.push(p);
                            });
                            spacedGroups.push(toExpression(lastSpacedGroup));
                            rule.value = toValue(spacedGroups);
                        }
                    });
                }
            };

            module.exports = ToCSSVisitor;

        }, { "../tree": 60, "./visitor": 88 }],
        88: [function(require, module, exports) {
            var tree = require("../tree");

            var _visitArgs = { visitDeeper: true },
                _hasIndexed = false;

            function _noop(node) {
                return node;
            }

            function indexNodeTypes(parent, ticker) {
                // add .typeIndex to tree node types for lookup table
                var key, child;
                for (key in parent) {
                    if (parent.hasOwnProperty(key)) {
                        child = parent[key];
                        switch (typeof child) {
                            case "function":
                                // ignore bound functions directly on tree which do not have a prototype
                                // or aren't nodes
                                if (child.prototype && child.prototype.type) {
                                    child.prototype.typeIndex = ticker++;
                                }
                                break;
                            case "object":
                                ticker = indexNodeTypes(child, ticker);
                                break;
                        }
                    }
                }
                return ticker;
            }

            var Visitor = function(implementation) {
                this._implementation = implementation;
                this._visitFnCache = [];

                if (!_hasIndexed) {
                    indexNodeTypes(tree, 1);
                    _hasIndexed = true;
                }
            };

            Visitor.prototype = {
                visit: function(node) {
                    if (!node) {
                        return node;
                    }

                    var nodeTypeIndex = node.typeIndex;
                    if (!nodeTypeIndex) {
                        return node;
                    }

                    var visitFnCache = this._visitFnCache,
                        impl = this._implementation,
                        aryIndx = nodeTypeIndex << 1,
                        outAryIndex = aryIndx | 1,
                        func = visitFnCache[aryIndx],
                        funcOut = visitFnCache[outAryIndex],
                        visitArgs = _visitArgs,
                        fnName;

                    visitArgs.visitDeeper = true;

                    if (!func) {
                        fnName = "visit" + node.type;
                        func = impl[fnName] || _noop;
                        funcOut = impl[fnName + "Out"] || _noop;
                        visitFnCache[aryIndx] = func;
                        visitFnCache[outAryIndex] = funcOut;
                    }

                    if (func !== _noop) {
                        var newNode = func.call(impl, node, visitArgs);
                        if (impl.isReplacing) {
                            node = newNode;
                        }
                    }

                    if (visitArgs.visitDeeper && node && node.accept) {
                        node.accept(this);
                    }

                    if (funcOut != _noop) {
                        funcOut.call(impl, node);
                    }

                    return node;
                },
                visitArray: function(nodes, nonReplacing) {
                    if (!nodes) {
                        return nodes;
                    }

                    var cnt = nodes.length,
                        i;

                    // Non-replacing
                    if (nonReplacing || !this._implementation.isReplacing) {
                        for (i = 0; i < cnt; i++) {
                            this.visit(nodes[i]);
                        }
                        return nodes;
                    }

                    // Replacing
                    var out = [];
                    for (i = 0; i < cnt; i++) {
                        var evald = this.visit(nodes[i]);
                        if (evald === undefined) { continue; }
                        if (!evald.splice) {
                            out.push(evald);
                        } else if (evald.length) {
                            this.flatten(evald, out);
                        }
                    }
                    return out;
                },
                flatten: function(arr, out) {
                    if (!out) {
                        out = [];
                    }

                    var cnt, i, item,
                        nestedCnt, j, nestedItem;

                    for (i = 0, cnt = arr.length; i < cnt; i++) {
                        item = arr[i];
                        if (item === undefined) {
                            continue;
                        }
                        if (!item.splice) {
                            out.push(item);
                            continue;
                        }

                        for (j = 0, nestedCnt = item.length; j < nestedCnt; j++) {
                            nestedItem = item[j];
                            if (nestedItem === undefined) {
                                continue;
                            }
                            if (!nestedItem.splice) {
                                out.push(nestedItem);
                            } else if (nestedItem.length) {
                                this.flatten(nestedItem, out);
                            }
                        }
                    }

                    return out;
                }
            };
            module.exports = Visitor;

        }, { "../tree": 60 }],
        89: [function(require, module, exports) {
            // shim for using process in browser

            var process = module.exports = {};
            var queue = [];
            var draining = false;

            function drainQueue() {
                if (draining) {
                    return;
                }
                draining = true;
                var currentQueue;
                var len = queue.length;
                while (len) {
                    currentQueue = queue;
                    queue = [];
                    var i = -1;
                    while (++i < len) {
                        currentQueue[i]();
                    }
                    len = queue.length;
                }
                draining = false;
            }
            process.nextTick = function(fun) {
                queue.push(fun);
                if (!draining) {
                    setTimeout(drainQueue, 0);
                }
            };

            process.title = 'browser';
            process.browser = true;
            process.env = {};
            process.argv = [];
            process.version = ''; // empty string to avoid regexp issues
            process.versions = {};

            function noop() {}

            process.on = noop;
            process.addListener = noop;
            process.once = noop;
            process.off = noop;
            process.removeListener = noop;
            process.removeAllListeners = noop;
            process.emit = noop;

            process.binding = function(name) {
                throw new Error('process.binding is not supported');
            };

            // TODO(shtylman)
            process.cwd = function() { return '/' };
            process.chdir = function(dir) {
                throw new Error('process.chdir is not supported');
            };
            process.umask = function() { return 0; };

        }, {}],
        90: [function(require, module, exports) {
            'use strict';

            var asap = require('asap')

            module.exports = Promise;

            function Promise(fn) {
                if (typeof this !== 'object') throw new TypeError('Promises must be constructed via new')
                if (typeof fn !== 'function') throw new TypeError('not a function')
                var state = null
                var value = null
                var deferreds = []
                var self = this

                this.then = function(onFulfilled, onRejected) {
                    return new self.constructor(function(resolve, reject) {
                        handle(new Handler(onFulfilled, onRejected, resolve, reject))
                    })
                }

                function handle(deferred) {
                    if (state === null) {
                        deferreds.push(deferred)
                        return
                    }
                    asap(function() {
                        var cb = state ? deferred.onFulfilled : deferred.onRejected
                        if (cb === null) {
                            (state ? deferred.resolve : deferred.reject)(value)
                            return
                        }
                        var ret
                        try {
                            ret = cb(value)
                        } catch (e) {
                            deferred.reject(e)
                            return
                        }
                        deferred.resolve(ret)
                    })
                }

                function resolve(newValue) {
                    try { //Promise Resolution Procedure: https://github.com/promises-aplus/promises-spec#the-promise-resolution-procedure
                        if (newValue === self) throw new TypeError('A promise cannot be resolved with itself.')
                        if (newValue && (typeof newValue === 'object' || typeof newValue === 'function')) {
                            var then = newValue.then
                            if (typeof then === 'function') {
                                doResolve(then.bind(newValue), resolve, reject)
                                return
                            }
                        }
                        state = true
                        value = newValue
                        finale()
                    } catch (e) { reject(e) }
                }

                function reject(newValue) {
                    state = false
                    value = newValue
                    finale()
                }

                function finale() {
                    for (var i = 0, len = deferreds.length; i < len; i++)
                        handle(deferreds[i])
                    deferreds = null
                }

                doResolve(fn, resolve, reject)
            }


            function Handler(onFulfilled, onRejected, resolve, reject) {
                this.onFulfilled = typeof onFulfilled === 'function' ? onFulfilled : null
                this.onRejected = typeof onRejected === 'function' ? onRejected : null
                this.resolve = resolve
                this.reject = reject
            }

            /**
             * Take a potentially misbehaving resolver function and make sure
             * onFulfilled and onRejected are only called once.
             *
             * Makes no guarantees about asynchrony.
             */
            function doResolve(fn, onFulfilled, onRejected) {
                var done = false;
                try {
                    fn(function(value) {
                        if (done) return
                        done = true
                        onFulfilled(value)
                    }, function(reason) {
                        if (done) return
                        done = true
                        onRejected(reason)
                    })
                } catch (ex) {
                    if (done) return
                    done = true
                    onRejected(ex)
                }
            }

        }, { "asap": 92 }],
        91: [function(require, module, exports) {
            'use strict';

            //This file contains the ES6 extensions to the core Promises/A+ API

            var Promise = require('./core.js')
            var asap = require('asap')

            module.exports = Promise

            /* Static Functions */

            function ValuePromise(value) {
                this.then = function(onFulfilled) {
                    if (typeof onFulfilled !== 'function') return this
                    return new Promise(function(resolve, reject) {
                        asap(function() {
                            try {
                                resolve(onFulfilled(value))
                            } catch (ex) {
                                reject(ex);
                            }
                        })
                    })
                }
            }
            ValuePromise.prototype = Promise.prototype

            var TRUE = new ValuePromise(true)
            var FALSE = new ValuePromise(false)
            var NULL = new ValuePromise(null)
            var UNDEFINED = new ValuePromise(undefined)
            var ZERO = new ValuePromise(0)
            var EMPTYSTRING = new ValuePromise('')

            Promise.resolve = function(value) {
                if (value instanceof Promise) return value

                if (value === null) return NULL
                if (value === undefined) return UNDEFINED
                if (value === true) return TRUE
                if (value === false) return FALSE
                if (value === 0) return ZERO
                if (value === '') return EMPTYSTRING

                if (typeof value === 'object' || typeof value === 'function') {
                    try {
                        var then = value.then
                        if (typeof then === 'function') {
                            return new Promise(then.bind(value))
                        }
                    } catch (ex) {
                        return new Promise(function(resolve, reject) {
                            reject(ex)
                        })
                    }
                }

                return new ValuePromise(value)
            }

            Promise.all = function(arr) {
                var args = Array.prototype.slice.call(arr)

                return new Promise(function(resolve, reject) {
                    if (args.length === 0) return resolve([])
                    var remaining = args.length

                    function res(i, val) {
                        try {
                            if (val && (typeof val === 'object' || typeof val === 'function')) {
                                var then = val.then
                                if (typeof then === 'function') {
                                    then.call(val, function(val) { res(i, val) }, reject)
                                    return
                                }
                            }
                            args[i] = val
                            if (--remaining === 0) {
                                resolve(args);
                            }
                        } catch (ex) {
                            reject(ex)
                        }
                    }
                    for (var i = 0; i < args.length; i++) {
                        res(i, args[i])
                    }
                })
            }

            Promise.reject = function(value) {
                return new Promise(function(resolve, reject) {
                    reject(value);
                });
            }

            Promise.race = function(values) {
                return new Promise(function(resolve, reject) {
                    values.forEach(function(value) {
                        Promise.resolve(value).then(resolve, reject);
                    })
                });
            }

            /* Prototype Methods */

            Promise.prototype['catch'] = function(onRejected) {
                return this.then(null, onRejected);
            }

        }, { "./core.js": 90, "asap": 92 }],
        92: [function(require, module, exports) {
            (function(process) {

                // Use the fastest possible means to execute a task in a future turn
                // of the event loop.

                // linked list of tasks (single, with head node)
                var head = { task: void 0, next: null };
                var tail = head;
                var flushing = false;
                var requestFlush = void 0;
                var isNodeJS = false;

                function flush() {
                    /* jshint loopfunc: true */

                    while (head.next) {
                        head = head.next;
                        var task = head.task;
                        head.task = void 0;
                        var domain = head.domain;

                        if (domain) {
                            head.domain = void 0;
                            domain.enter();
                        }

                        try {
                            task();

                        } catch (e) {
                            if (isNodeJS) {
                                // In node, uncaught exceptions are considered fatal errors.
                                // Re-throw them synchronously to interrupt flushing!

                                // Ensure continuation if the uncaught exception is suppressed
                                // listening "uncaughtException" events (as domains does).
                                // Continue in next event to avoid tick recursion.
                                if (domain) {
                                    domain.exit();
                                }
                                setTimeout(flush, 0);
                                if (domain) {
                                    domain.enter();
                                }

                                throw e;

                            } else {
                                // In browsers, uncaught exceptions are not fatal.
                                // Re-throw them asynchronously to avoid slow-downs.
                                setTimeout(function() {
                                    throw e;
                                }, 0);
                            }
                        }

                        if (domain) {
                            domain.exit();
                        }
                    }

                    flushing = false;
                }

                if (typeof process !== "undefined" && process.nextTick) {
                    // Node.js before 0.9. Note that some fake-Node environments, like the
                    // Mocha test runner, introduce a `process` global without a `nextTick`.
                    isNodeJS = true;

                    requestFlush = function() {
                        process.nextTick(flush);
                    };

                } else if (typeof setImmediate === "function") {
                    // In IE10, Node.js 0.9+, or https://github.com/NobleJS/setImmediate
                    if (typeof window !== "undefined") {
                        requestFlush = setImmediate.bind(window, flush);
                    } else {
                        requestFlush = function() {
                            setImmediate(flush);
                        };
                    }

                } else if (typeof MessageChannel !== "undefined") {
                    // modern browsers
                    // http://www.nonblocking.io/2011/06/windownexttick.html
                    var channel = new MessageChannel();
                    channel.port1.onmessage = flush;
                    requestFlush = function() {
                        channel.port2.postMessage(0);
                    };

                } else {
                    // old browsers
                    requestFlush = function() {
                        setTimeout(flush, 0);
                    };
                }

                function asap(task) {
                    tail = tail.next = {
                        task: task,
                        domain: isNodeJS && process.domain,
                        next: null
                    };

                    if (!flushing) {
                        flushing = true;
                        requestFlush();
                    }
                };

                module.exports = asap;


            }).call(this, require('_process'))
        }, { "_process": 89 }],
        93: [function(require, module, exports) {
            // should work in any browser without browserify

            if (typeof Promise.prototype.done !== 'function') {
                Promise.prototype.done = function(onFulfilled, onRejected) {
                    var self = arguments.length ? this.then.apply(this, arguments) : this
                    self.then(null, function(err) {
                        setTimeout(function() {
                            throw err
                        }, 0)
                    })
                }
            }
        }, {}],
        94: [function(require, module, exports) {
            // not "use strict" so we can declare global "Promise"

            var asap = require('asap');

            if (typeof Promise === 'undefined') {
                Promise = require('./lib/core.js')
                require('./lib/es6-extensions.js')
            }

            require('./polyfill-done.js');

        }, { "./lib/core.js": 90, "./lib/es6-extensions.js": 91, "./polyfill-done.js": 93, "asap": 92 }]
    }, {}, [2])(2)
});
s